diff --git a/bin/configs/csharp-netcore-OpenAPIClient.yaml b/bin/configs/csharp-netcore-OpenAPIClient.yaml
index 22734fef4542..d7b96a7bf16f 100644
--- a/bin/configs/csharp-netcore-OpenAPIClient.yaml
+++ b/bin/configs/csharp-netcore-OpenAPIClient.yaml
@@ -4,4 +4,5 @@ inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-e
 templateDir: modules/openapi-generator/src/main/resources/csharp-netcore
 additionalProperties:
   packageGuid: '{321C8C3F-0156-40C1-AE42-D59761FB9B6C}'
-  useCompareNetObjects: "true"
+  useCompareNetObjects: true 
+  disallowAdditionalPropertiesIfNotPresent: false
diff --git a/modules/openapi-generator/src/main/resources/csharp-netcore/model.mustache b/modules/openapi-generator/src/main/resources/csharp-netcore/model.mustache
index d952a614719a..26ce826e0301 100644
--- a/modules/openapi-generator/src/main/resources/csharp-netcore/model.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp-netcore/model.mustache
@@ -25,9 +25,9 @@ using OpenAPIDateConverter = {{packageName}}.Client.OpenAPIDateConverter;
 {{#useCompareNetObjects}}
 using OpenAPIClientUtils = {{packageName}}.Client.ClientUtils;
 {{/useCompareNetObjects}}
-
 {{#models}}
 {{#model}}
+
 namespace {{packageName}}.{{modelPackage}}
 {
 {{#isEnum}}{{>modelEnum}}{{/isEnum}}{{^isEnum}}{{>modelGeneric}}{{/isEnum}}
diff --git a/modules/openapi-generator/src/main/resources/csharp-netcore/modelGeneric.mustache b/modules/openapi-generator/src/main/resources/csharp-netcore/modelGeneric.mustache
index aa94c5557915..0c2548c44b85 100644
--- a/modules/openapi-generator/src/main/resources/csharp-netcore/modelGeneric.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp-netcore/modelGeneric.mustache
@@ -43,7 +43,15 @@
         /// Initializes a new instance of the <see cref="{{classname}}" /> class.
         /// </summary>
         [JsonConstructorAttribute]
+        {{^isAdditionalPropertiesTrue}}
         protected {{classname}}() { }
+        {{/isAdditionalPropertiesTrue}}
+        {{#isAdditionalPropertiesTrue}}
+        protected {{classname}}()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
+        {{/isAdditionalPropertiesTrue}}
     {{/hasOnlyReadOnly}}
     {{/hasRequired}}
         /// <summary>
@@ -92,6 +100,9 @@
             {{/isReadOnly}}
             {{/isInherited}}
             {{/vars}}
+            {{#isAdditionalPropertiesTrue}}
+            this.AdditionalProperties = new Dictionary<string, object>();
+            {{/isAdditionalPropertiesTrue}}
         }
 
         {{#vars}}
@@ -101,13 +112,23 @@
         /// {{^description}}Gets or Sets {{{name}}}{{/description}}{{#description}}{{description}}{{/description}}
         /// </summary>{{#description}}
         /// <value>{{description}}</value>{{/description}}
-        [DataMember(Name = "{{baseName}}", EmitDefaultValue = {{#vendorExtensions.x-emit-default-value}}true{{/vendorExtensions.x-emit-default-value}}{{^vendorExtensions.x-emit-default-value}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/vendorExtensions.x-emit-default-value}})]{{#isDate}}
-        [JsonConverter(typeof(OpenAPIDateConverter))]{{/isDate}}
+        [DataMember(Name = "{{baseName}}", EmitDefaultValue = {{#vendorExtensions.x-emit-default-value}}true{{/vendorExtensions.x-emit-default-value}}{{^vendorExtensions.x-emit-default-value}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/vendorExtensions.x-emit-default-value}})]
+        {{#isDate}}
+        [JsonConverter(typeof(OpenAPIDateConverter))]
+        {{/isDate}}
         public {{{dataType}}} {{name}} { get; {{#isReadOnly}}private {{/isReadOnly}}set; }
 
         {{/isEnum}}
         {{/isInherited}}
         {{/vars}}
+        {{#isAdditionalPropertiesTrue}}
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
+        {{/isAdditionalPropertiesTrue}}
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -122,6 +143,9 @@
             {{#vars}}
             sb.Append("  {{name}}: ").Append({{name}}).Append("\n");
             {{/vars}}
+            {{#isAdditionalPropertiesTrue}}
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
+            {{/isAdditionalPropertiesTrue}}
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -180,7 +204,10 @@
                     {{^vendorExtensions.x-is-value-type}}this.{{name}} != null &&
                     input.{{name}} != null &&
                     {{/vendorExtensions.x-is-value-type}}this.{{name}}.SequenceEqual(input.{{name}})
-                ){{#hasMore}} && {{/hasMore}}{{/isContainer}}{{/vars}}{{^vars}}{{#parent}}base.Equals(input){{/parent}}{{^parent}}false{{/parent}}{{/vars}};
+                ){{#hasMore}} && {{/hasMore}}{{/isContainer}}{{/vars}}{{^vars}}{{#parent}}base.Equals(input){{/parent}}{{^parent}}false{{/parent}}{{/vars}}{{^isAdditionalPropertiesTrue}};{{/isAdditionalPropertiesTrue}}
+                {{#isAdditionalPropertiesTrue}}
+                && (this.AdditionalProperties.Count == input.AdditionalProperties.Count && !this.AdditionalProperties.Except(input.AdditionalProperties).Any());
+                {{/isAdditionalPropertiesTrue}}
             {{/useCompareNetObjects}}
         }
 
@@ -207,6 +234,10 @@
                 hashCode = hashCode * 59 + this.{{name}}.GetHashCode();
                 {{/vendorExtensions.x-is-value-type}}
                 {{/vars}}
+                {{#isAdditionalPropertiesTrue}}
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
+                {{/isAdditionalPropertiesTrue}}
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/PetTests.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/PetTests.cs
index a680938da9cc..eb7a585e6ff2 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/PetTests.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools.Test/Model/PetTests.cs
@@ -105,6 +105,17 @@ public void TestSerialization()
             // create pet
             Pet p1 = new Pet(name: "Csharp test", photoUrls: new List<string> { "http://petstore.com/csharp_test" });
             Assert.Equal("{\"name\":\"Csharp test\",\"photoUrls\":[\"http://petstore.com/csharp_test\"]}", JsonConvert.SerializeObject(p1));
+
+            // test additonal properties (serialization)
+            Pet p2 = new Pet(name: "Csharp test", photoUrls: new List<string> { "http://petstore.com/csharp_test" });
+            p2.AdditionalProperties.Add("hello", "world");
+            Assert.Equal("{\"name\":\"Csharp test\",\"photoUrls\":[\"http://petstore.com/csharp_test\"],\"hello\":\"world\"}", JsonConvert.SerializeObject(p2));
+
+            // test additonal properties (deserialization)
+            Pet p3 = JsonConvert.DeserializeObject<Pet>("{\"name\":\"Csharp test\",\"photoUrls\":[\"http://petstore.com/csharp_test\"],\"hello\":\"world\",\"int\":123}");
+            Assert.Equal("Csharp test", p3.Name);
+            Assert.Equal("world", p3.AdditionalProperties["hello"]);
+            Assert.Equal(123L, p3.AdditionalProperties["int"]);
         }
 
         /// <summary>
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesAnyType.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesAnyType.cs
deleted file mode 100644
index fe9de3aa27cf..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesAnyType.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesAnyType
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesAnyType : Dictionary<String, Object>,  IEquatable<AdditionalPropertiesAnyType>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesAnyType" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesAnyType(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesAnyType {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesAnyType).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesAnyType instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesAnyType to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesAnyType input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesArray.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesArray.cs
deleted file mode 100644
index 46e6973df032..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesArray.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesArray
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesArray : Dictionary<String, List>,  IEquatable<AdditionalPropertiesArray>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesArray" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesArray(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesArray {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesArray).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesArray instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesArray to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesArray input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesBoolean.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesBoolean.cs
deleted file mode 100644
index e21c5085cefa..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesBoolean.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesBoolean
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesBoolean : Dictionary<String, bool>,  IEquatable<AdditionalPropertiesBoolean>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesBoolean" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesBoolean(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesBoolean {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesBoolean).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesBoolean instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesBoolean to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesBoolean input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs
index 89ec5cacfe86..368ae0e998c9 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs
@@ -40,6 +40,7 @@ public partial class AdditionalPropertiesClass : IEquatable<AdditionalProperties
         {
             this.MapProperty = mapProperty;
             this.MapOfMapProperty = mapOfMapProperty;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -54,6 +55,12 @@ public partial class AdditionalPropertiesClass : IEquatable<AdditionalProperties
         [DataMember(Name = "map_of_map_property", EmitDefaultValue = false)]
         public Dictionary<string, Dictionary<string, string>> MapOfMapProperty { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -64,6 +71,7 @@ public override string ToString()
             sb.Append("class AdditionalPropertiesClass {\n");
             sb.Append("  MapProperty: ").Append(MapProperty).Append("\n");
             sb.Append("  MapOfMapProperty: ").Append(MapOfMapProperty).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -110,6 +118,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.MapProperty.GetHashCode();
                 if (this.MapOfMapProperty != null)
                     hashCode = hashCode * 59 + this.MapOfMapProperty.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesInteger.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesInteger.cs
deleted file mode 100644
index ceff9d7354e4..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesInteger.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesInteger
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesInteger : Dictionary<String, int>,  IEquatable<AdditionalPropertiesInteger>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesInteger" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesInteger(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesInteger {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesInteger).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesInteger instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesInteger to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesInteger input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesNumber.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesNumber.cs
deleted file mode 100644
index db37cf7ce657..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesNumber.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesNumber
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesNumber : Dictionary<String, decimal>,  IEquatable<AdditionalPropertiesNumber>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesNumber" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesNumber(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesNumber {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesNumber).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesNumber instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesNumber to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesNumber input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesObject.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesObject.cs
deleted file mode 100644
index ee5b67b2ebd1..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesObject.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesObject
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesObject : Dictionary<String, Dictionary<String, Object>>,  IEquatable<AdditionalPropertiesObject>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesObject" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesObject(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesObject {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesObject).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesObject instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesObject to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesObject input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesString.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesString.cs
deleted file mode 100644
index 29dbad58cac7..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AdditionalPropertiesString.cs
+++ /dev/null
@@ -1,119 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AdditionalPropertiesString
-    /// </summary>
-    [DataContract]
-    public partial class AdditionalPropertiesString : Dictionary<String, string>,  IEquatable<AdditionalPropertiesString>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AdditionalPropertiesString" /> class.
-        /// </summary>
-        /// <param name="name">name.</param>
-        public AdditionalPropertiesString(string name = default(string)) : base()
-        {
-            this.Name = name;
-        }
-        
-        /// <summary>
-        /// Gets or Sets Name
-        /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
-        public string Name { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AdditionalPropertiesString {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Name: ").Append(Name).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as AdditionalPropertiesString).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if AdditionalPropertiesString instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AdditionalPropertiesString to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AdditionalPropertiesString input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                if (this.Name != null)
-                    hashCode = hashCode * 59 + this.Name.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs
index e8ee350b38be..fd02679a53d8 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs
@@ -41,7 +41,10 @@ public partial class Animal : IEquatable<Animal>, IValidatableObject
         /// Initializes a new instance of the <see cref="Animal" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Animal() { }
+        protected Animal()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Animal" /> class.
         /// </summary>
@@ -53,6 +56,7 @@ protected Animal() { }
             this.ClassName = className ?? throw new ArgumentNullException("className is a required property for Animal and cannot be null");
             // use default value if no "color" provided
             this.Color = color ?? "red";
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -67,6 +71,12 @@ protected Animal() { }
         [DataMember(Name = "color", EmitDefaultValue = false)]
         public string Color { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -77,6 +87,7 @@ public override string ToString()
             sb.Append("class Animal {\n");
             sb.Append("  ClassName: ").Append(ClassName).Append("\n");
             sb.Append("  Color: ").Append(Color).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -123,6 +134,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.ClassName.GetHashCode();
                 if (this.Color != null)
                     hashCode = hashCode * 59 + this.Color.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AnimalFarm.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AnimalFarm.cs
deleted file mode 100644
index b4ebc8d959c0..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/AnimalFarm.cs
+++ /dev/null
@@ -1,111 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * OpenAPI spec version: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// AnimalFarm
-    /// </summary>
-    [DataContract]
-    public partial class AnimalFarm : List<Animal>,  IEquatable<AnimalFarm>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AnimalFarm" /> class.
-        /// </summary>
-        [JsonConstructorAttribute]
-        public AnimalFarm() : base()
-        {
-        }
-        
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class AnimalFarm {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return this.Equals(input as AnimalFarm);
-        }
-
-        /// <summary>
-        /// Returns true if AnimalFarm instances are equal
-        /// </summary>
-        /// <param name="input">Instance of AnimalFarm to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(AnimalFarm input)
-        {
-            if (input == null)
-                return false;
-
-            return base.Equals(input);
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ApiResponse.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ApiResponse.cs
index b23c90ca4b51..15d1c02b2b02 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ApiResponse.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ApiResponse.cs
@@ -42,6 +42,7 @@ public partial class ApiResponse : IEquatable<ApiResponse>, IValidatableObject
             this.Code = code;
             this.Type = type;
             this.Message = message;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -62,6 +63,12 @@ public partial class ApiResponse : IEquatable<ApiResponse>, IValidatableObject
         [DataMember(Name = "message", EmitDefaultValue = false)]
         public string Message { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -73,6 +80,7 @@ public override string ToString()
             sb.Append("  Code: ").Append(Code).Append("\n");
             sb.Append("  Type: ").Append(Type).Append("\n");
             sb.Append("  Message: ").Append(Message).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -120,6 +128,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.Type.GetHashCode();
                 if (this.Message != null)
                     hashCode = hashCode * 59 + this.Message.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs
index d069b1313c85..1b90907f02b1 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs
@@ -38,6 +38,7 @@ public partial class ArrayOfArrayOfNumberOnly : IEquatable<ArrayOfArrayOfNumberO
         public ArrayOfArrayOfNumberOnly(List<List<decimal>> arrayArrayNumber = default(List<List<decimal>>))
         {
             this.ArrayArrayNumber = arrayArrayNumber;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class ArrayOfArrayOfNumberOnly : IEquatable<ArrayOfArrayOfNumberO
         [DataMember(Name = "ArrayArrayNumber", EmitDefaultValue = false)]
         public List<List<decimal>> ArrayArrayNumber { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class ArrayOfArrayOfNumberOnly {\n");
             sb.Append("  ArrayArrayNumber: ").Append(ArrayArrayNumber).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.ArrayArrayNumber != null)
                     hashCode = hashCode * 59 + this.ArrayArrayNumber.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfNumberOnly.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfNumberOnly.cs
index 43b4a3ee9b75..16a5cfd12c99 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfNumberOnly.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayOfNumberOnly.cs
@@ -38,6 +38,7 @@ public partial class ArrayOfNumberOnly : IEquatable<ArrayOfNumberOnly>, IValidat
         public ArrayOfNumberOnly(List<decimal> arrayNumber = default(List<decimal>))
         {
             this.ArrayNumber = arrayNumber;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class ArrayOfNumberOnly : IEquatable<ArrayOfNumberOnly>, IValidat
         [DataMember(Name = "ArrayNumber", EmitDefaultValue = false)]
         public List<decimal> ArrayNumber { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class ArrayOfNumberOnly {\n");
             sb.Append("  ArrayNumber: ").Append(ArrayNumber).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.ArrayNumber != null)
                     hashCode = hashCode * 59 + this.ArrayNumber.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayTest.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayTest.cs
index aa283d3403eb..6f84a8be3e79 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayTest.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ArrayTest.cs
@@ -42,6 +42,7 @@ public partial class ArrayTest : IEquatable<ArrayTest>, IValidatableObject
             this.ArrayOfString = arrayOfString;
             this.ArrayArrayOfInteger = arrayArrayOfInteger;
             this.ArrayArrayOfModel = arrayArrayOfModel;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -62,6 +63,12 @@ public partial class ArrayTest : IEquatable<ArrayTest>, IValidatableObject
         [DataMember(Name = "array_array_of_model", EmitDefaultValue = false)]
         public List<List<ReadOnlyFirst>> ArrayArrayOfModel { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -73,6 +80,7 @@ public override string ToString()
             sb.Append("  ArrayOfString: ").Append(ArrayOfString).Append("\n");
             sb.Append("  ArrayArrayOfInteger: ").Append(ArrayArrayOfInteger).Append("\n");
             sb.Append("  ArrayArrayOfModel: ").Append(ArrayArrayOfModel).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -121,6 +129,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.ArrayArrayOfInteger.GetHashCode();
                 if (this.ArrayArrayOfModel != null)
                     hashCode = hashCode * 59 + this.ArrayArrayOfModel.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/BigCat.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/BigCat.cs
deleted file mode 100644
index 2fd960256c46..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/BigCat.cs
+++ /dev/null
@@ -1,158 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// BigCat
-    /// </summary>
-    [DataContract]
-    public partial class BigCat : Cat,  IEquatable<BigCat>, IValidatableObject
-    {
-        /// <summary>
-        /// Defines Kind
-        /// </summary>
-        [JsonConverter(typeof(StringEnumConverter))]
-        public enum KindEnum
-        {
-            /// <summary>
-            /// Enum Lions for value: lions
-            /// </summary>
-            [EnumMember(Value = "lions")]
-            Lions = 1,
-
-            /// <summary>
-            /// Enum Tigers for value: tigers
-            /// </summary>
-            [EnumMember(Value = "tigers")]
-            Tigers = 2,
-
-            /// <summary>
-            /// Enum Leopards for value: leopards
-            /// </summary>
-            [EnumMember(Value = "leopards")]
-            Leopards = 3,
-
-            /// <summary>
-            /// Enum Jaguars for value: jaguars
-            /// </summary>
-            [EnumMember(Value = "jaguars")]
-            Jaguars = 4
-
-        }
-
-        /// <summary>
-        /// Gets or Sets Kind
-        /// </summary>
-        [DataMember(Name="kind", EmitDefaultValue=false)]
-        public KindEnum? Kind { get; set; }
-        /// <summary>
-        /// Initializes a new instance of the <see cref="BigCat" /> class.
-        /// </summary>
-        [JsonConstructorAttribute]
-        protected BigCat() { }
-        /// <summary>
-        /// Initializes a new instance of the <see cref="BigCat" /> class.
-        /// </summary>
-        /// <param name="kind">kind.</param>
-        /// <param name="className">className (required).</param>
-        /// <param name="color">color (default to &quot;red&quot;).</param>
-        /// <param name="declawed">declawed.</param>
-        public BigCat(KindEnum? kind = default(KindEnum?), string className = default(string), string color = "red", bool declawed = default(bool)) : base(declawed)
-        {
-            this.Kind = kind;
-        }
-        
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class BigCat {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("  Kind: ").Append(Kind).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public override string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as BigCat).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if BigCat instances are equal
-        /// </summary>
-        /// <param name="input">Instance of BigCat to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(BigCat input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                hashCode = hashCode * 59 + this.Kind.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            foreach(var x in BaseValidate(validationContext)) yield return x;
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/BigCatAllOf.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/BigCatAllOf.cs
deleted file mode 100644
index 5244a8f34882..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/BigCatAllOf.cs
+++ /dev/null
@@ -1,148 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// BigCatAllOf
-    /// </summary>
-    [DataContract]
-    public partial class BigCatAllOf :  IEquatable<BigCatAllOf>, IValidatableObject
-    {
-        /// <summary>
-        /// Defines Kind
-        /// </summary>
-        [JsonConverter(typeof(StringEnumConverter))]
-        public enum KindEnum
-        {
-            /// <summary>
-            /// Enum Lions for value: lions
-            /// </summary>
-            [EnumMember(Value = "lions")]
-            Lions = 1,
-
-            /// <summary>
-            /// Enum Tigers for value: tigers
-            /// </summary>
-            [EnumMember(Value = "tigers")]
-            Tigers = 2,
-
-            /// <summary>
-            /// Enum Leopards for value: leopards
-            /// </summary>
-            [EnumMember(Value = "leopards")]
-            Leopards = 3,
-
-            /// <summary>
-            /// Enum Jaguars for value: jaguars
-            /// </summary>
-            [EnumMember(Value = "jaguars")]
-            Jaguars = 4
-
-        }
-
-        /// <summary>
-        /// Gets or Sets Kind
-        /// </summary>
-        [DataMember(Name="kind", EmitDefaultValue=false)]
-        public KindEnum? Kind { get; set; }
-        /// <summary>
-        /// Initializes a new instance of the <see cref="BigCatAllOf" /> class.
-        /// </summary>
-        /// <param name="kind">kind.</param>
-        public BigCatAllOf(KindEnum? kind = default(KindEnum?))
-        {
-            this.Kind = kind;
-        }
-        
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class BigCatAllOf {\n");
-            sb.Append("  Kind: ").Append(Kind).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public virtual string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as BigCatAllOf).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if BigCatAllOf instances are equal
-        /// </summary>
-        /// <param name="input">Instance of BigCatAllOf to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(BigCatAllOf input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = 41;
-                hashCode = hashCode * 59 + this.Kind.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Capitalization.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Capitalization.cs
index d8f6d0e16b73..54a68abcbe1a 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Capitalization.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Capitalization.cs
@@ -48,6 +48,7 @@ public partial class Capitalization : IEquatable<Capitalization>, IValidatableOb
             this.CapitalSnake = capitalSnake;
             this.SCAETHFlowPoints = sCAETHFlowPoints;
             this.ATT_NAME = aTTNAME;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -87,6 +88,12 @@ public partial class Capitalization : IEquatable<Capitalization>, IValidatableOb
         [DataMember(Name = "ATT_NAME", EmitDefaultValue = false)]
         public string ATT_NAME { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -101,6 +108,7 @@ public override string ToString()
             sb.Append("  CapitalSnake: ").Append(CapitalSnake).Append("\n");
             sb.Append("  SCAETHFlowPoints: ").Append(SCAETHFlowPoints).Append("\n");
             sb.Append("  ATT_NAME: ").Append(ATT_NAME).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -155,6 +163,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.SCAETHFlowPoints.GetHashCode();
                 if (this.ATT_NAME != null)
                     hashCode = hashCode * 59 + this.ATT_NAME.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
index 36301ec6388d..bec79a75940e 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
@@ -35,7 +35,10 @@ public partial class Cat : Animal, IEquatable<Cat>, IValidatableObject
         /// Initializes a new instance of the <see cref="Cat" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Cat() { }
+        protected Cat()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Cat" /> class.
         /// </summary>
@@ -45,6 +48,7 @@ protected Cat() { }
         public Cat(bool declawed = default(bool), string className = "Cat", string color = "red") : base(className, color)
         {
             this.Declawed = declawed;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -53,6 +57,12 @@ protected Cat() { }
         [DataMember(Name = "declawed", EmitDefaultValue = false)]
         public bool Declawed { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -63,6 +73,7 @@ public override string ToString()
             sb.Append("class Cat {\n");
             sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
             sb.Append("  Declawed: ").Append(Declawed).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -106,6 +117,8 @@ public override int GetHashCode()
             {
                 int hashCode = base.GetHashCode();
                 hashCode = hashCode * 59 + this.Declawed.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/CatAllOf.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/CatAllOf.cs
index 1bda8d00dc81..62b350eb041a 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/CatAllOf.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/CatAllOf.cs
@@ -38,6 +38,7 @@ public partial class CatAllOf : IEquatable<CatAllOf>, IValidatableObject
         public CatAllOf(bool declawed = default(bool))
         {
             this.Declawed = declawed;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class CatAllOf : IEquatable<CatAllOf>, IValidatableObject
         [DataMember(Name = "declawed", EmitDefaultValue = false)]
         public bool Declawed { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class CatAllOf {\n");
             sb.Append("  Declawed: ").Append(Declawed).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -98,6 +106,8 @@ public override int GetHashCode()
             {
                 int hashCode = 41;
                 hashCode = hashCode * 59 + this.Declawed.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Category.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Category.cs
index 2d8b422cf89b..fe4be5254661 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Category.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Category.cs
@@ -35,7 +35,10 @@ public partial class Category : IEquatable<Category>, IValidatableObject
         /// Initializes a new instance of the <see cref="Category" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Category() { }
+        protected Category()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Category" /> class.
         /// </summary>
@@ -46,6 +49,7 @@ protected Category() { }
             // to ensure "name" is required (not null)
             this.Name = name ?? throw new ArgumentNullException("name is a required property for Category and cannot be null");
             this.Id = id;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -60,6 +64,12 @@ protected Category() { }
         [DataMember(Name = "name", EmitDefaultValue = false)]
         public string Name { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -70,6 +80,7 @@ public override string ToString()
             sb.Append("class Category {\n");
             sb.Append("  Id: ").Append(Id).Append("\n");
             sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -115,6 +126,8 @@ public override int GetHashCode()
                 hashCode = hashCode * 59 + this.Id.GetHashCode();
                 if (this.Name != null)
                     hashCode = hashCode * 59 + this.Name.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ClassModel.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ClassModel.cs
index ae482ee8633d..fe84bf5dc6e7 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ClassModel.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ClassModel.cs
@@ -38,6 +38,7 @@ public partial class ClassModel : IEquatable<ClassModel>, IValidatableObject
         public ClassModel(string _class = default(string))
         {
             this.Class = _class;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class ClassModel : IEquatable<ClassModel>, IValidatableObject
         [DataMember(Name = "_class", EmitDefaultValue = false)]
         public string Class { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class ClassModel {\n");
             sb.Append("  Class: ").Append(Class).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.Class != null)
                     hashCode = hashCode * 59 + this.Class.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
index 15b7a28ef1a4..220ada0748b3 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
@@ -35,7 +35,10 @@ public partial class Dog : Animal, IEquatable<Dog>, IValidatableObject
         /// Initializes a new instance of the <see cref="Dog" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Dog() { }
+        protected Dog()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Dog" /> class.
         /// </summary>
@@ -45,6 +48,7 @@ protected Dog() { }
         public Dog(string breed = default(string), string className = "Dog", string color = "red") : base(className, color)
         {
             this.Breed = breed;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -53,6 +57,12 @@ protected Dog() { }
         [DataMember(Name = "breed", EmitDefaultValue = false)]
         public string Breed { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -63,6 +73,7 @@ public override string ToString()
             sb.Append("class Dog {\n");
             sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
             sb.Append("  Breed: ").Append(Breed).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -107,6 +118,8 @@ public override int GetHashCode()
                 int hashCode = base.GetHashCode();
                 if (this.Breed != null)
                     hashCode = hashCode * 59 + this.Breed.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/DogAllOf.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/DogAllOf.cs
index 1ed12cc90419..b0090fa88c92 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/DogAllOf.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/DogAllOf.cs
@@ -38,6 +38,7 @@ public partial class DogAllOf : IEquatable<DogAllOf>, IValidatableObject
         public DogAllOf(string breed = default(string))
         {
             this.Breed = breed;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class DogAllOf : IEquatable<DogAllOf>, IValidatableObject
         [DataMember(Name = "breed", EmitDefaultValue = false)]
         public string Breed { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class DogAllOf {\n");
             sb.Append("  Breed: ").Append(Breed).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.Breed != null)
                     hashCode = hashCode * 59 + this.Breed.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumArrays.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumArrays.cs
index 303638b9e7b5..38f24381c450 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumArrays.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumArrays.cs
@@ -91,8 +91,15 @@ public enum ArrayEnumEnum
         {
             this.JustSymbol = justSymbol;
             this.ArrayEnum = arrayEnum;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -103,6 +110,7 @@ public override string ToString()
             sb.Append("class EnumArrays {\n");
             sb.Append("  JustSymbol: ").Append(JustSymbol).Append("\n");
             sb.Append("  ArrayEnum: ").Append(ArrayEnum).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -147,6 +155,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 hashCode = hashCode * 59 + this.JustSymbol.GetHashCode();
                 hashCode = hashCode * 59 + this.ArrayEnum.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumTest.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumTest.cs
index 6adf138cebb7..d9576b09a9f1 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumTest.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/EnumTest.cs
@@ -164,7 +164,10 @@ public enum EnumNumberEnum
         /// Initializes a new instance of the <see cref="EnumTest" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected EnumTest() { }
+        protected EnumTest()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="EnumTest" /> class.
         /// </summary>
@@ -186,8 +189,15 @@ protected EnumTest() { }
             this.OuterEnumInteger = outerEnumInteger;
             this.OuterEnumDefaultValue = outerEnumDefaultValue;
             this.OuterEnumIntegerDefaultValue = outerEnumIntegerDefaultValue;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -204,6 +214,7 @@ public override string ToString()
             sb.Append("  OuterEnumInteger: ").Append(OuterEnumInteger).Append("\n");
             sb.Append("  OuterEnumDefaultValue: ").Append(OuterEnumDefaultValue).Append("\n");
             sb.Append("  OuterEnumIntegerDefaultValue: ").Append(OuterEnumIntegerDefaultValue).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -254,6 +265,8 @@ public override int GetHashCode()
                 hashCode = hashCode * 59 + this.OuterEnumInteger.GetHashCode();
                 hashCode = hashCode * 59 + this.OuterEnumDefaultValue.GetHashCode();
                 hashCode = hashCode * 59 + this.OuterEnumIntegerDefaultValue.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/File.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/File.cs
index 2506f3fcc05d..58cf7206c5e1 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/File.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/File.cs
@@ -38,6 +38,7 @@ public partial class File : IEquatable<File>, IValidatableObject
         public File(string sourceURI = default(string))
         {
             this.SourceURI = sourceURI;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -47,6 +48,12 @@ public partial class File : IEquatable<File>, IValidatableObject
         [DataMember(Name = "sourceURI", EmitDefaultValue = false)]
         public string SourceURI { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -56,6 +63,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class File {\n");
             sb.Append("  SourceURI: ").Append(SourceURI).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -100,6 +108,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.SourceURI != null)
                     hashCode = hashCode * 59 + this.SourceURI.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FileSchemaTestClass.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FileSchemaTestClass.cs
index a9fd3ee15419..7b171faf1f21 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FileSchemaTestClass.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FileSchemaTestClass.cs
@@ -40,6 +40,7 @@ public partial class FileSchemaTestClass : IEquatable<FileSchemaTestClass>, IVal
         {
             this.File = file;
             this.Files = files;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -54,6 +55,12 @@ public partial class FileSchemaTestClass : IEquatable<FileSchemaTestClass>, IVal
         [DataMember(Name = "files", EmitDefaultValue = false)]
         public List<File> Files { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -64,6 +71,7 @@ public override string ToString()
             sb.Append("class FileSchemaTestClass {\n");
             sb.Append("  File: ").Append(File).Append("\n");
             sb.Append("  Files: ").Append(Files).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -110,6 +118,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.File.GetHashCode();
                 if (this.Files != null)
                     hashCode = hashCode * 59 + this.Files.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Foo.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Foo.cs
index 5b3c0a2dbd17..840f083d3e3f 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Foo.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Foo.cs
@@ -39,6 +39,7 @@ public Foo(string bar = "bar")
         {
             // use default value if no "bar" provided
             this.Bar = bar ?? "bar";
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -47,6 +48,12 @@ public Foo(string bar = "bar")
         [DataMember(Name = "bar", EmitDefaultValue = false)]
         public string Bar { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -56,6 +63,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class Foo {\n");
             sb.Append("  Bar: ").Append(Bar).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -100,6 +108,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.Bar != null)
                     hashCode = hashCode * 59 + this.Bar.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FormatTest.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FormatTest.cs
index b9b836c20261..cc97b2ee568e 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FormatTest.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/FormatTest.cs
@@ -35,7 +35,10 @@ public partial class FormatTest : IEquatable<FormatTest>, IValidatableObject
         /// Initializes a new instance of the <see cref="FormatTest" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected FormatTest() { }
+        protected FormatTest()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="FormatTest" /> class.
         /// </summary>
@@ -73,6 +76,7 @@ protected FormatTest() { }
             this.Uuid = uuid;
             this.PatternWithDigits = patternWithDigits;
             this.PatternWithDigitsAndDelimiter = patternWithDigitsAndDelimiter;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -168,6 +172,12 @@ protected FormatTest() { }
         [DataMember(Name = "pattern_with_digits_and_delimiter", EmitDefaultValue = false)]
         public string PatternWithDigitsAndDelimiter { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -191,6 +201,7 @@ public override string ToString()
             sb.Append("  Password: ").Append(Password).Append("\n");
             sb.Append("  PatternWithDigits: ").Append(PatternWithDigits).Append("\n");
             sb.Append("  PatternWithDigitsAndDelimiter: ").Append(PatternWithDigitsAndDelimiter).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -257,6 +268,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.PatternWithDigits.GetHashCode();
                 if (this.PatternWithDigitsAndDelimiter != null)
                     hashCode = hashCode * 59 + this.PatternWithDigitsAndDelimiter.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HasOnlyReadOnly.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HasOnlyReadOnly.cs
index d50bb270d7ab..393c368c48ab 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HasOnlyReadOnly.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HasOnlyReadOnly.cs
@@ -37,6 +37,7 @@ public partial class HasOnlyReadOnly : IEquatable<HasOnlyReadOnly>, IValidatable
         [JsonConstructorAttribute]
         public HasOnlyReadOnly()
         {
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -51,6 +52,12 @@ public HasOnlyReadOnly()
         [DataMember(Name = "foo", EmitDefaultValue = false)]
         public string Foo { get; private set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -61,6 +68,7 @@ public override string ToString()
             sb.Append("class HasOnlyReadOnly {\n");
             sb.Append("  Bar: ").Append(Bar).Append("\n");
             sb.Append("  Foo: ").Append(Foo).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -107,6 +115,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.Bar.GetHashCode();
                 if (this.Foo != null)
                     hashCode = hashCode * 59 + this.Foo.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HealthCheckResult.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HealthCheckResult.cs
index 7207eebef1b9..ad2dca66f64c 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HealthCheckResult.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/HealthCheckResult.cs
@@ -38,6 +38,7 @@ public partial class HealthCheckResult : IEquatable<HealthCheckResult>, IValidat
         public HealthCheckResult(string nullableMessage = default(string))
         {
             this.NullableMessage = nullableMessage;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class HealthCheckResult : IEquatable<HealthCheckResult>, IValidat
         [DataMember(Name = "NullableMessage", EmitDefaultValue = true)]
         public string NullableMessage { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class HealthCheckResult {\n");
             sb.Append("  NullableMessage: ").Append(NullableMessage).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.NullableMessage != null)
                     hashCode = hashCode * 59 + this.NullableMessage.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject.cs
index 066f6b1440a8..780185519bfa 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject.cs
@@ -40,6 +40,7 @@ public partial class InlineObject : IEquatable<InlineObject>, IValidatableObject
         {
             this.Name = name;
             this.Status = status;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -56,6 +57,12 @@ public partial class InlineObject : IEquatable<InlineObject>, IValidatableObject
         [DataMember(Name = "status", EmitDefaultValue = false)]
         public string Status { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -66,6 +73,7 @@ public override string ToString()
             sb.Append("class InlineObject {\n");
             sb.Append("  Name: ").Append(Name).Append("\n");
             sb.Append("  Status: ").Append(Status).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -112,6 +120,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.Name.GetHashCode();
                 if (this.Status != null)
                     hashCode = hashCode * 59 + this.Status.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject1.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject1.cs
index 67f66d3b74bb..3ef70aa5ab29 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject1.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject1.cs
@@ -40,6 +40,7 @@ public partial class InlineObject1 : IEquatable<InlineObject1>, IValidatableObje
         {
             this.AdditionalMetadata = additionalMetadata;
             this.File = file;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -56,6 +57,12 @@ public partial class InlineObject1 : IEquatable<InlineObject1>, IValidatableObje
         [DataMember(Name = "file", EmitDefaultValue = false)]
         public System.IO.Stream File { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -66,6 +73,7 @@ public override string ToString()
             sb.Append("class InlineObject1 {\n");
             sb.Append("  AdditionalMetadata: ").Append(AdditionalMetadata).Append("\n");
             sb.Append("  File: ").Append(File).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -112,6 +120,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.AdditionalMetadata.GetHashCode();
                 if (this.File != null)
                     hashCode = hashCode * 59 + this.File.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject2.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject2.cs
index 53ccb46c383f..7d73efc1f9fd 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject2.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject2.cs
@@ -100,8 +100,15 @@ public enum EnumFormStringEnum
         {
             this.EnumFormStringArray = enumFormStringArray;
             this.EnumFormString = enumFormString;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -112,6 +119,7 @@ public override string ToString()
             sb.Append("class InlineObject2 {\n");
             sb.Append("  EnumFormStringArray: ").Append(EnumFormStringArray).Append("\n");
             sb.Append("  EnumFormString: ").Append(EnumFormString).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -156,6 +164,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 hashCode = hashCode * 59 + this.EnumFormStringArray.GetHashCode();
                 hashCode = hashCode * 59 + this.EnumFormString.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject3.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject3.cs
index 6e3d21e76185..4b0e02ecf9be 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject3.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject3.cs
@@ -35,7 +35,10 @@ public partial class InlineObject3 : IEquatable<InlineObject3>, IValidatableObje
         /// Initializes a new instance of the <see cref="InlineObject3" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected InlineObject3() { }
+        protected InlineObject3()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="InlineObject3" /> class.
         /// </summary>
@@ -71,6 +74,7 @@ protected InlineObject3() { }
             this.DateTime = dateTime;
             this.Password = password;
             this.Callback = callback;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -172,6 +176,12 @@ protected InlineObject3() { }
         [DataMember(Name = "callback", EmitDefaultValue = false)]
         public string Callback { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -194,6 +204,7 @@ public override string ToString()
             sb.Append("  DateTime: ").Append(DateTime).Append("\n");
             sb.Append("  Password: ").Append(Password).Append("\n");
             sb.Append("  Callback: ").Append(Callback).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -258,6 +269,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.Password.GetHashCode();
                 if (this.Callback != null)
                     hashCode = hashCode * 59 + this.Callback.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject4.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject4.cs
index e86c6e2521c9..c89ac96f6136 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject4.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject4.cs
@@ -35,7 +35,10 @@ public partial class InlineObject4 : IEquatable<InlineObject4>, IValidatableObje
         /// Initializes a new instance of the <see cref="InlineObject4" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected InlineObject4() { }
+        protected InlineObject4()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="InlineObject4" /> class.
         /// </summary>
@@ -47,6 +50,7 @@ protected InlineObject4() { }
             this.Param = param ?? throw new ArgumentNullException("param is a required property for InlineObject4 and cannot be null");
             // to ensure "param2" is required (not null)
             this.Param2 = param2 ?? throw new ArgumentNullException("param2 is a required property for InlineObject4 and cannot be null");
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -63,6 +67,12 @@ protected InlineObject4() { }
         [DataMember(Name = "param2", EmitDefaultValue = false)]
         public string Param2 { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -73,6 +83,7 @@ public override string ToString()
             sb.Append("class InlineObject4 {\n");
             sb.Append("  Param: ").Append(Param).Append("\n");
             sb.Append("  Param2: ").Append(Param2).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -119,6 +130,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.Param.GetHashCode();
                 if (this.Param2 != null)
                     hashCode = hashCode * 59 + this.Param2.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject5.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject5.cs
index 8a54c118a94d..a0890701fdf4 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject5.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineObject5.cs
@@ -35,7 +35,10 @@ public partial class InlineObject5 : IEquatable<InlineObject5>, IValidatableObje
         /// Initializes a new instance of the <see cref="InlineObject5" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected InlineObject5() { }
+        protected InlineObject5()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="InlineObject5" /> class.
         /// </summary>
@@ -46,6 +49,7 @@ protected InlineObject5() { }
             // to ensure "requiredFile" is required (not null)
             this.RequiredFile = requiredFile ?? throw new ArgumentNullException("requiredFile is a required property for InlineObject5 and cannot be null");
             this.AdditionalMetadata = additionalMetadata;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -62,6 +66,12 @@ protected InlineObject5() { }
         [DataMember(Name = "requiredFile", EmitDefaultValue = false)]
         public System.IO.Stream RequiredFile { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -72,6 +82,7 @@ public override string ToString()
             sb.Append("class InlineObject5 {\n");
             sb.Append("  AdditionalMetadata: ").Append(AdditionalMetadata).Append("\n");
             sb.Append("  RequiredFile: ").Append(RequiredFile).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -118,6 +129,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.AdditionalMetadata.GetHashCode();
                 if (this.RequiredFile != null)
                     hashCode = hashCode * 59 + this.RequiredFile.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineResponseDefault.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineResponseDefault.cs
index 90658d9ee075..22fb6f061ef0 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineResponseDefault.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/InlineResponseDefault.cs
@@ -38,6 +38,7 @@ public partial class InlineResponseDefault : IEquatable<InlineResponseDefault>,
         public InlineResponseDefault(Foo _string = default(Foo))
         {
             this.String = _string;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class InlineResponseDefault : IEquatable<InlineResponseDefault>,
         [DataMember(Name = "string", EmitDefaultValue = false)]
         public Foo String { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class InlineResponseDefault {\n");
             sb.Append("  String: ").Append(String).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.String != null)
                     hashCode = hashCode * 59 + this.String.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/List.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/List.cs
index 08726324fe4d..5acef9a2037f 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/List.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/List.cs
@@ -38,6 +38,7 @@ public partial class List : IEquatable<List>, IValidatableObject
         public List(string _123list = default(string))
         {
             this._123List = _123list;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class List : IEquatable<List>, IValidatableObject
         [DataMember(Name = "123-list", EmitDefaultValue = false)]
         public string _123List { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class List {\n");
             sb.Append("  _123List: ").Append(_123List).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this._123List != null)
                     hashCode = hashCode * 59 + this._123List.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MapTest.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MapTest.cs
index 83fb41cc023c..31f6e37b6411 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MapTest.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MapTest.cs
@@ -70,6 +70,7 @@ public enum InnerEnum
             this.MapOfEnumString = mapOfEnumString;
             this.DirectMap = directMap;
             this.IndirectMap = indirectMap;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -90,6 +91,12 @@ public enum InnerEnum
         [DataMember(Name = "indirect_map", EmitDefaultValue = false)]
         public Dictionary<string, bool> IndirectMap { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -102,6 +109,7 @@ public override string ToString()
             sb.Append("  MapOfEnumString: ").Append(MapOfEnumString).Append("\n");
             sb.Append("  DirectMap: ").Append(DirectMap).Append("\n");
             sb.Append("  IndirectMap: ").Append(IndirectMap).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -151,6 +159,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.DirectMap.GetHashCode();
                 if (this.IndirectMap != null)
                     hashCode = hashCode * 59 + this.IndirectMap.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MixedPropertiesAndAdditionalPropertiesClass.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MixedPropertiesAndAdditionalPropertiesClass.cs
index 2d07c103683d..1cefa4f96886 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MixedPropertiesAndAdditionalPropertiesClass.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/MixedPropertiesAndAdditionalPropertiesClass.cs
@@ -42,6 +42,7 @@ public partial class MixedPropertiesAndAdditionalPropertiesClass : IEquatable<Mi
             this.Uuid = uuid;
             this.DateTime = dateTime;
             this.Map = map;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -62,6 +63,12 @@ public partial class MixedPropertiesAndAdditionalPropertiesClass : IEquatable<Mi
         [DataMember(Name = "map", EmitDefaultValue = false)]
         public Dictionary<string, Animal> Map { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -73,6 +80,7 @@ public override string ToString()
             sb.Append("  Uuid: ").Append(Uuid).Append("\n");
             sb.Append("  DateTime: ").Append(DateTime).Append("\n");
             sb.Append("  Map: ").Append(Map).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -121,6 +129,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.DateTime.GetHashCode();
                 if (this.Map != null)
                     hashCode = hashCode * 59 + this.Map.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Model200Response.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Model200Response.cs
index bb2df767af18..5cdf53a7fff1 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Model200Response.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Model200Response.cs
@@ -40,6 +40,7 @@ public partial class Model200Response : IEquatable<Model200Response>, IValidatab
         {
             this.Name = name;
             this.Class = _class;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -54,6 +55,12 @@ public partial class Model200Response : IEquatable<Model200Response>, IValidatab
         [DataMember(Name = "class", EmitDefaultValue = false)]
         public string Class { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -64,6 +71,7 @@ public override string ToString()
             sb.Append("class Model200Response {\n");
             sb.Append("  Name: ").Append(Name).Append("\n");
             sb.Append("  Class: ").Append(Class).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -109,6 +117,8 @@ public override int GetHashCode()
                 hashCode = hashCode * 59 + this.Name.GetHashCode();
                 if (this.Class != null)
                     hashCode = hashCode * 59 + this.Class.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ModelClient.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ModelClient.cs
index 62eaa7e2d841..e0b44ec83ec8 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ModelClient.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ModelClient.cs
@@ -38,6 +38,7 @@ public partial class ModelClient : IEquatable<ModelClient>, IValidatableObject
         public ModelClient(string _client = default(string))
         {
             this.__Client = _client;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class ModelClient : IEquatable<ModelClient>, IValidatableObject
         [DataMember(Name = "client", EmitDefaultValue = false)]
         public string __Client { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class ModelClient {\n");
             sb.Append("  __Client: ").Append(__Client).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -99,6 +107,8 @@ public override int GetHashCode()
                 int hashCode = 41;
                 if (this.__Client != null)
                     hashCode = hashCode * 59 + this.__Client.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Name.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Name.cs
index 04c5cadbcf9c..45009b6ff007 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Name.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Name.cs
@@ -35,7 +35,10 @@ public partial class Name : IEquatable<Name>, IValidatableObject
         /// Initializes a new instance of the <see cref="Name" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Name() { }
+        protected Name()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Name" /> class.
         /// </summary>
@@ -45,6 +48,7 @@ protected Name() { }
         {
             this._Name = name;
             this.Property = property;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -71,6 +75,12 @@ protected Name() { }
         [DataMember(Name = "123Number", EmitDefaultValue = false)]
         public int _123Number { get; private set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -83,6 +93,7 @@ public override string ToString()
             sb.Append("  SnakeCase: ").Append(SnakeCase).Append("\n");
             sb.Append("  Property: ").Append(Property).Append("\n");
             sb.Append("  _123Number: ").Append(_123Number).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -130,6 +141,8 @@ public override int GetHashCode()
                 if (this.Property != null)
                     hashCode = hashCode * 59 + this.Property.GetHashCode();
                 hashCode = hashCode * 59 + this._123Number.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/NumberOnly.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/NumberOnly.cs
index 8b1aeccff9ca..60715977fc19 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/NumberOnly.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/NumberOnly.cs
@@ -38,6 +38,7 @@ public partial class NumberOnly : IEquatable<NumberOnly>, IValidatableObject
         public NumberOnly(decimal justNumber = default(decimal))
         {
             this.JustNumber = justNumber;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class NumberOnly : IEquatable<NumberOnly>, IValidatableObject
         [DataMember(Name = "JustNumber", EmitDefaultValue = false)]
         public decimal JustNumber { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class NumberOnly {\n");
             sb.Append("  JustNumber: ").Append(JustNumber).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -98,6 +106,8 @@ public override int GetHashCode()
             {
                 int hashCode = 41;
                 hashCode = hashCode * 59 + this.JustNumber.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Order.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Order.cs
index 46fdacf2c261..2f8576883994 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Order.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Order.cs
@@ -81,6 +81,7 @@ public enum StatusEnum
             this.ShipDate = shipDate;
             this.Status = status;
             this.Complete = complete;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -113,6 +114,12 @@ public enum StatusEnum
         [DataMember(Name = "complete", EmitDefaultValue = false)]
         public bool Complete { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -127,6 +134,7 @@ public override string ToString()
             sb.Append("  ShipDate: ").Append(ShipDate).Append("\n");
             sb.Append("  Status: ").Append(Status).Append("\n");
             sb.Append("  Complete: ").Append(Complete).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -176,6 +184,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.ShipDate.GetHashCode();
                 hashCode = hashCode * 59 + this.Status.GetHashCode();
                 hashCode = hashCode * 59 + this.Complete.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/OuterComposite.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/OuterComposite.cs
index da99d557f0f8..4a045b7d3a46 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/OuterComposite.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/OuterComposite.cs
@@ -42,6 +42,7 @@ public partial class OuterComposite : IEquatable<OuterComposite>, IValidatableOb
             this.MyNumber = myNumber;
             this.MyString = myString;
             this.MyBoolean = myBoolean;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -62,6 +63,12 @@ public partial class OuterComposite : IEquatable<OuterComposite>, IValidatableOb
         [DataMember(Name = "my_boolean", EmitDefaultValue = false)]
         public bool MyBoolean { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -73,6 +80,7 @@ public override string ToString()
             sb.Append("  MyNumber: ").Append(MyNumber).Append("\n");
             sb.Append("  MyString: ").Append(MyString).Append("\n");
             sb.Append("  MyBoolean: ").Append(MyBoolean).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -119,6 +127,8 @@ public override int GetHashCode()
                 if (this.MyString != null)
                     hashCode = hashCode * 59 + this.MyString.GetHashCode();
                 hashCode = hashCode * 59 + this.MyBoolean.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Pet.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Pet.cs
index 1b23c5a56995..3d4c5d0bd169 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Pet.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Pet.cs
@@ -68,7 +68,10 @@ public enum StatusEnum
         /// Initializes a new instance of the <see cref="Pet" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Pet() { }
+        protected Pet()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Pet" /> class.
         /// </summary>
@@ -88,6 +91,7 @@ protected Pet() { }
             this.Category = category;
             this.Tags = tags;
             this.Status = status;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -120,6 +124,12 @@ protected Pet() { }
         [DataMember(Name = "tags", EmitDefaultValue = false)]
         public List<Tag> Tags { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -134,6 +144,7 @@ public override string ToString()
             sb.Append("  PhotoUrls: ").Append(PhotoUrls).Append("\n");
             sb.Append("  Tags: ").Append(Tags).Append("\n");
             sb.Append("  Status: ").Append(Status).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -186,6 +197,8 @@ public override int GetHashCode()
                 if (this.Tags != null)
                     hashCode = hashCode * 59 + this.Tags.GetHashCode();
                 hashCode = hashCode * 59 + this.Status.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ReadOnlyFirst.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ReadOnlyFirst.cs
index 3f92367c6a50..266b65c27963 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ReadOnlyFirst.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/ReadOnlyFirst.cs
@@ -38,6 +38,7 @@ public partial class ReadOnlyFirst : IEquatable<ReadOnlyFirst>, IValidatableObje
         public ReadOnlyFirst(string baz = default(string))
         {
             this.Baz = baz;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -52,6 +53,12 @@ public partial class ReadOnlyFirst : IEquatable<ReadOnlyFirst>, IValidatableObje
         [DataMember(Name = "baz", EmitDefaultValue = false)]
         public string Baz { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -62,6 +69,7 @@ public override string ToString()
             sb.Append("class ReadOnlyFirst {\n");
             sb.Append("  Bar: ").Append(Bar).Append("\n");
             sb.Append("  Baz: ").Append(Baz).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -108,6 +116,8 @@ public override int GetHashCode()
                     hashCode = hashCode * 59 + this.Bar.GetHashCode();
                 if (this.Baz != null)
                     hashCode = hashCode * 59 + this.Baz.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Return.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Return.cs
index a88f522a26b8..eb2042fd6572 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Return.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Return.cs
@@ -38,6 +38,7 @@ public partial class Return : IEquatable<Return>, IValidatableObject
         public Return(int _return = default(int))
         {
             this._Return = _return;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class Return : IEquatable<Return>, IValidatableObject
         [DataMember(Name = "return", EmitDefaultValue = false)]
         public int _Return { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class Return {\n");
             sb.Append("  _Return: ").Append(_Return).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -98,6 +106,8 @@ public override int GetHashCode()
             {
                 int hashCode = 41;
                 hashCode = hashCode * 59 + this._Return.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/SpecialModelName.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/SpecialModelName.cs
index 4898e79a4580..5d59e568149e 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/SpecialModelName.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/SpecialModelName.cs
@@ -38,6 +38,7 @@ public partial class SpecialModelName : IEquatable<SpecialModelName>, IValidatab
         public SpecialModelName(long specialPropertyName = default(long))
         {
             this.SpecialPropertyName = specialPropertyName;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -46,6 +47,12 @@ public partial class SpecialModelName : IEquatable<SpecialModelName>, IValidatab
         [DataMember(Name = "$special[property.name]", EmitDefaultValue = false)]
         public long SpecialPropertyName { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -55,6 +62,7 @@ public override string ToString()
             var sb = new StringBuilder();
             sb.Append("class SpecialModelName {\n");
             sb.Append("  SpecialPropertyName: ").Append(SpecialPropertyName).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -98,6 +106,8 @@ public override int GetHashCode()
             {
                 int hashCode = 41;
                 hashCode = hashCode * 59 + this.SpecialPropertyName.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/StringBooleanMap.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/StringBooleanMap.cs
deleted file mode 100644
index 65457a6ece88..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/StringBooleanMap.cs
+++ /dev/null
@@ -1,111 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * OpenAPI spec version: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// StringBooleanMap
-    /// </summary>
-    [DataContract]
-    public partial class StringBooleanMap : Dictionary<String, bool?>,  IEquatable<StringBooleanMap>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="StringBooleanMap" /> class.
-        /// </summary>
-        [JsonConstructorAttribute]
-        public StringBooleanMap() : base()
-        {
-        }
-        
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class StringBooleanMap {\n");
-            sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return this.Equals(input as StringBooleanMap);
-        }
-
-        /// <summary>
-        /// Returns true if StringBooleanMap instances are equal
-        /// </summary>
-        /// <param name="input">Instance of StringBooleanMap to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(StringBooleanMap input)
-        {
-            if (input == null)
-                return false;
-
-            return base.Equals(input);
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = base.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Tag.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Tag.cs
index 1fbde976e396..cf8aa3667219 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Tag.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Tag.cs
@@ -40,6 +40,7 @@ public partial class Tag : IEquatable<Tag>, IValidatableObject
         {
             this.Id = id;
             this.Name = name;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -54,6 +55,12 @@ public partial class Tag : IEquatable<Tag>, IValidatableObject
         [DataMember(Name = "name", EmitDefaultValue = false)]
         public string Name { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -64,6 +71,7 @@ public override string ToString()
             sb.Append("class Tag {\n");
             sb.Append("  Id: ").Append(Id).Append("\n");
             sb.Append("  Name: ").Append(Name).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -109,6 +117,8 @@ public override int GetHashCode()
                 hashCode = hashCode * 59 + this.Id.GetHashCode();
                 if (this.Name != null)
                     hashCode = hashCode * 59 + this.Name.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/TypeHolderDefault.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/TypeHolderDefault.cs
deleted file mode 100644
index c7034a2edda5..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/TypeHolderDefault.cs
+++ /dev/null
@@ -1,166 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// TypeHolderDefault
-    /// </summary>
-    [DataContract]
-    public partial class TypeHolderDefault :  IEquatable<TypeHolderDefault>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="TypeHolderDefault" /> class.
-        /// </summary>
-        [JsonConstructorAttribute]
-        protected TypeHolderDefault() { }
-        /// <summary>
-        /// Initializes a new instance of the <see cref="TypeHolderDefault" /> class.
-        /// </summary>
-        /// <param name="stringItem">stringItem (required) (default to &quot;what&quot;).</param>
-        /// <param name="numberItem">numberItem (required).</param>
-        /// <param name="integerItem">integerItem (required).</param>
-        /// <param name="boolItem">boolItem (required) (default to true).</param>
-        /// <param name="arrayItem">arrayItem (required).</param>
-        public TypeHolderDefault(string stringItem = "what", decimal numberItem = default(decimal), int integerItem = default(int), bool boolItem = true, List<int> arrayItem = default(List<int>))
-        {
-            // to ensure "stringItem" is required (not null)
-            this.StringItem = stringItem ?? throw new ArgumentNullException("stringItem is a required property for TypeHolderDefault and cannot be null");
-            this.NumberItem = numberItem;
-            this.IntegerItem = integerItem;
-            this.BoolItem = boolItem;
-            // to ensure "arrayItem" is required (not null)
-            this.ArrayItem = arrayItem ?? throw new ArgumentNullException("arrayItem is a required property for TypeHolderDefault and cannot be null");
-        }
-        
-        /// <summary>
-        /// Gets or Sets StringItem
-        /// </summary>
-        [DataMember(Name="string_item", EmitDefaultValue=false)]
-        public string StringItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NumberItem
-        /// </summary>
-        [DataMember(Name="number_item", EmitDefaultValue=false)]
-        public decimal NumberItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets IntegerItem
-        /// </summary>
-        [DataMember(Name="integer_item", EmitDefaultValue=false)]
-        public int IntegerItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets BoolItem
-        /// </summary>
-        [DataMember(Name="bool_item", EmitDefaultValue=false)]
-        public bool BoolItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets ArrayItem
-        /// </summary>
-        [DataMember(Name="array_item", EmitDefaultValue=false)]
-        public List<int> ArrayItem { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class TypeHolderDefault {\n");
-            sb.Append("  StringItem: ").Append(StringItem).Append("\n");
-            sb.Append("  NumberItem: ").Append(NumberItem).Append("\n");
-            sb.Append("  IntegerItem: ").Append(IntegerItem).Append("\n");
-            sb.Append("  BoolItem: ").Append(BoolItem).Append("\n");
-            sb.Append("  ArrayItem: ").Append(ArrayItem).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public virtual string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as TypeHolderDefault).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if TypeHolderDefault instances are equal
-        /// </summary>
-        /// <param name="input">Instance of TypeHolderDefault to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(TypeHolderDefault input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = 41;
-                if (this.StringItem != null)
-                    hashCode = hashCode * 59 + this.StringItem.GetHashCode();
-                hashCode = hashCode * 59 + this.NumberItem.GetHashCode();
-                hashCode = hashCode * 59 + this.IntegerItem.GetHashCode();
-                hashCode = hashCode * 59 + this.BoolItem.GetHashCode();
-                if (this.ArrayItem != null)
-                    hashCode = hashCode * 59 + this.ArrayItem.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/TypeHolderExample.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/TypeHolderExample.cs
deleted file mode 100644
index e69ce97ac715..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/TypeHolderExample.cs
+++ /dev/null
@@ -1,176 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// TypeHolderExample
-    /// </summary>
-    [DataContract]
-    public partial class TypeHolderExample :  IEquatable<TypeHolderExample>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="TypeHolderExample" /> class.
-        /// </summary>
-        [JsonConstructorAttribute]
-        protected TypeHolderExample() { }
-        /// <summary>
-        /// Initializes a new instance of the <see cref="TypeHolderExample" /> class.
-        /// </summary>
-        /// <param name="stringItem">stringItem (required).</param>
-        /// <param name="numberItem">numberItem (required).</param>
-        /// <param name="floatItem">floatItem (required).</param>
-        /// <param name="integerItem">integerItem (required).</param>
-        /// <param name="boolItem">boolItem (required).</param>
-        /// <param name="arrayItem">arrayItem (required).</param>
-        public TypeHolderExample(string stringItem = default(string), decimal numberItem = default(decimal), float floatItem = default(float), int integerItem = default(int), bool boolItem = default(bool), List<int> arrayItem = default(List<int>))
-        {
-            // to ensure "stringItem" is required (not null)
-            this.StringItem = stringItem ?? throw new ArgumentNullException("stringItem is a required property for TypeHolderExample and cannot be null");
-            this.NumberItem = numberItem;
-            this.FloatItem = floatItem;
-            this.IntegerItem = integerItem;
-            this.BoolItem = boolItem;
-            // to ensure "arrayItem" is required (not null)
-            this.ArrayItem = arrayItem ?? throw new ArgumentNullException("arrayItem is a required property for TypeHolderExample and cannot be null");
-        }
-        
-        /// <summary>
-        /// Gets or Sets StringItem
-        /// </summary>
-        [DataMember(Name="string_item", EmitDefaultValue=false)]
-        public string StringItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NumberItem
-        /// </summary>
-        [DataMember(Name="number_item", EmitDefaultValue=false)]
-        public decimal NumberItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets FloatItem
-        /// </summary>
-        [DataMember(Name="float_item", EmitDefaultValue=false)]
-        public float FloatItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets IntegerItem
-        /// </summary>
-        [DataMember(Name="integer_item", EmitDefaultValue=false)]
-        public int IntegerItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets BoolItem
-        /// </summary>
-        [DataMember(Name="bool_item", EmitDefaultValue=false)]
-        public bool BoolItem { get; set; }
-
-        /// <summary>
-        /// Gets or Sets ArrayItem
-        /// </summary>
-        [DataMember(Name="array_item", EmitDefaultValue=false)]
-        public List<int> ArrayItem { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class TypeHolderExample {\n");
-            sb.Append("  StringItem: ").Append(StringItem).Append("\n");
-            sb.Append("  NumberItem: ").Append(NumberItem).Append("\n");
-            sb.Append("  FloatItem: ").Append(FloatItem).Append("\n");
-            sb.Append("  IntegerItem: ").Append(IntegerItem).Append("\n");
-            sb.Append("  BoolItem: ").Append(BoolItem).Append("\n");
-            sb.Append("  ArrayItem: ").Append(ArrayItem).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public virtual string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as TypeHolderExample).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if TypeHolderExample instances are equal
-        /// </summary>
-        /// <param name="input">Instance of TypeHolderExample to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(TypeHolderExample input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = 41;
-                if (this.StringItem != null)
-                    hashCode = hashCode * 59 + this.StringItem.GetHashCode();
-                hashCode = hashCode * 59 + this.NumberItem.GetHashCode();
-                hashCode = hashCode * 59 + this.FloatItem.GetHashCode();
-                hashCode = hashCode * 59 + this.IntegerItem.GetHashCode();
-                hashCode = hashCode * 59 + this.BoolItem.GetHashCode();
-                if (this.ArrayItem != null)
-                    hashCode = hashCode * 59 + this.ArrayItem.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/User.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/User.cs
index 8b6ee8d2d479..cc92d4884803 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/User.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/User.cs
@@ -52,6 +52,7 @@ public partial class User : IEquatable<User>, IValidatableObject
             this.Password = password;
             this.Phone = phone;
             this.UserStatus = userStatus;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -103,6 +104,12 @@ public partial class User : IEquatable<User>, IValidatableObject
         [DataMember(Name = "userStatus", EmitDefaultValue = false)]
         public int UserStatus { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -119,6 +126,7 @@ public override string ToString()
             sb.Append("  Password: ").Append(Password).Append("\n");
             sb.Append("  Phone: ").Append(Phone).Append("\n");
             sb.Append("  UserStatus: ").Append(UserStatus).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -175,6 +183,8 @@ public override int GetHashCode()
                 if (this.Phone != null)
                     hashCode = hashCode * 59 + this.Phone.GetHashCode();
                 hashCode = hashCode * 59 + this.UserStatus.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/XmlItem.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/XmlItem.cs
deleted file mode 100644
index 8f204d8814f6..000000000000
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/XmlItem.cs
+++ /dev/null
@@ -1,411 +0,0 @@
-/* 
- * OpenAPI Petstore
- *
- * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
- *
- * The version of the OpenAPI document: 1.0.0
- * 
- * Generated by: https://github.com/openapitools/openapi-generator.git
- */
-
-
-using System;
-using System.Linq;
-using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Runtime.Serialization;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Converters;
-using System.ComponentModel.DataAnnotations;
-using OpenAPIDateConverter = Org.OpenAPITools.Client.OpenAPIDateConverter;
-using OpenAPIClientUtils = Org.OpenAPITools.Client.ClientUtils;
-
-namespace Org.OpenAPITools.Model
-{
-    /// <summary>
-    /// XmlItem
-    /// </summary>
-    [DataContract]
-    public partial class XmlItem :  IEquatable<XmlItem>, IValidatableObject
-    {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="XmlItem" /> class.
-        /// </summary>
-        /// <param name="attributeString">attributeString.</param>
-        /// <param name="attributeNumber">attributeNumber.</param>
-        /// <param name="attributeInteger">attributeInteger.</param>
-        /// <param name="attributeBoolean">attributeBoolean.</param>
-        /// <param name="wrappedArray">wrappedArray.</param>
-        /// <param name="nameString">nameString.</param>
-        /// <param name="nameNumber">nameNumber.</param>
-        /// <param name="nameInteger">nameInteger.</param>
-        /// <param name="nameBoolean">nameBoolean.</param>
-        /// <param name="nameArray">nameArray.</param>
-        /// <param name="nameWrappedArray">nameWrappedArray.</param>
-        /// <param name="prefixString">prefixString.</param>
-        /// <param name="prefixNumber">prefixNumber.</param>
-        /// <param name="prefixInteger">prefixInteger.</param>
-        /// <param name="prefixBoolean">prefixBoolean.</param>
-        /// <param name="prefixArray">prefixArray.</param>
-        /// <param name="prefixWrappedArray">prefixWrappedArray.</param>
-        /// <param name="namespaceString">namespaceString.</param>
-        /// <param name="namespaceNumber">namespaceNumber.</param>
-        /// <param name="namespaceInteger">namespaceInteger.</param>
-        /// <param name="namespaceBoolean">namespaceBoolean.</param>
-        /// <param name="namespaceArray">namespaceArray.</param>
-        /// <param name="namespaceWrappedArray">namespaceWrappedArray.</param>
-        /// <param name="prefixNsString">prefixNsString.</param>
-        /// <param name="prefixNsNumber">prefixNsNumber.</param>
-        /// <param name="prefixNsInteger">prefixNsInteger.</param>
-        /// <param name="prefixNsBoolean">prefixNsBoolean.</param>
-        /// <param name="prefixNsArray">prefixNsArray.</param>
-        /// <param name="prefixNsWrappedArray">prefixNsWrappedArray.</param>
-        public XmlItem(string attributeString = default(string), decimal attributeNumber = default(decimal), int attributeInteger = default(int), bool attributeBoolean = default(bool), List<int> wrappedArray = default(List<int>), string nameString = default(string), decimal nameNumber = default(decimal), int nameInteger = default(int), bool nameBoolean = default(bool), List<int> nameArray = default(List<int>), List<int> nameWrappedArray = default(List<int>), string prefixString = default(string), decimal prefixNumber = default(decimal), int prefixInteger = default(int), bool prefixBoolean = default(bool), List<int> prefixArray = default(List<int>), List<int> prefixWrappedArray = default(List<int>), string namespaceString = default(string), decimal namespaceNumber = default(decimal), int namespaceInteger = default(int), bool namespaceBoolean = default(bool), List<int> namespaceArray = default(List<int>), List<int> namespaceWrappedArray = default(List<int>), string prefixNsString = default(string), decimal prefixNsNumber = default(decimal), int prefixNsInteger = default(int), bool prefixNsBoolean = default(bool), List<int> prefixNsArray = default(List<int>), List<int> prefixNsWrappedArray = default(List<int>))
-        {
-            this.AttributeString = attributeString;
-            this.AttributeNumber = attributeNumber;
-            this.AttributeInteger = attributeInteger;
-            this.AttributeBoolean = attributeBoolean;
-            this.WrappedArray = wrappedArray;
-            this.NameString = nameString;
-            this.NameNumber = nameNumber;
-            this.NameInteger = nameInteger;
-            this.NameBoolean = nameBoolean;
-            this.NameArray = nameArray;
-            this.NameWrappedArray = nameWrappedArray;
-            this.PrefixString = prefixString;
-            this.PrefixNumber = prefixNumber;
-            this.PrefixInteger = prefixInteger;
-            this.PrefixBoolean = prefixBoolean;
-            this.PrefixArray = prefixArray;
-            this.PrefixWrappedArray = prefixWrappedArray;
-            this.NamespaceString = namespaceString;
-            this.NamespaceNumber = namespaceNumber;
-            this.NamespaceInteger = namespaceInteger;
-            this.NamespaceBoolean = namespaceBoolean;
-            this.NamespaceArray = namespaceArray;
-            this.NamespaceWrappedArray = namespaceWrappedArray;
-            this.PrefixNsString = prefixNsString;
-            this.PrefixNsNumber = prefixNsNumber;
-            this.PrefixNsInteger = prefixNsInteger;
-            this.PrefixNsBoolean = prefixNsBoolean;
-            this.PrefixNsArray = prefixNsArray;
-            this.PrefixNsWrappedArray = prefixNsWrappedArray;
-        }
-        
-        /// <summary>
-        /// Gets or Sets AttributeString
-        /// </summary>
-        [DataMember(Name="attribute_string", EmitDefaultValue=false)]
-        public string AttributeString { get; set; }
-
-        /// <summary>
-        /// Gets or Sets AttributeNumber
-        /// </summary>
-        [DataMember(Name="attribute_number", EmitDefaultValue=false)]
-        public decimal AttributeNumber { get; set; }
-
-        /// <summary>
-        /// Gets or Sets AttributeInteger
-        /// </summary>
-        [DataMember(Name="attribute_integer", EmitDefaultValue=false)]
-        public int AttributeInteger { get; set; }
-
-        /// <summary>
-        /// Gets or Sets AttributeBoolean
-        /// </summary>
-        [DataMember(Name="attribute_boolean", EmitDefaultValue=false)]
-        public bool AttributeBoolean { get; set; }
-
-        /// <summary>
-        /// Gets or Sets WrappedArray
-        /// </summary>
-        [DataMember(Name="wrapped_array", EmitDefaultValue=false)]
-        public List<int> WrappedArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NameString
-        /// </summary>
-        [DataMember(Name="name_string", EmitDefaultValue=false)]
-        public string NameString { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NameNumber
-        /// </summary>
-        [DataMember(Name="name_number", EmitDefaultValue=false)]
-        public decimal NameNumber { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NameInteger
-        /// </summary>
-        [DataMember(Name="name_integer", EmitDefaultValue=false)]
-        public int NameInteger { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NameBoolean
-        /// </summary>
-        [DataMember(Name="name_boolean", EmitDefaultValue=false)]
-        public bool NameBoolean { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NameArray
-        /// </summary>
-        [DataMember(Name="name_array", EmitDefaultValue=false)]
-        public List<int> NameArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NameWrappedArray
-        /// </summary>
-        [DataMember(Name="name_wrapped_array", EmitDefaultValue=false)]
-        public List<int> NameWrappedArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixString
-        /// </summary>
-        [DataMember(Name="prefix_string", EmitDefaultValue=false)]
-        public string PrefixString { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNumber
-        /// </summary>
-        [DataMember(Name="prefix_number", EmitDefaultValue=false)]
-        public decimal PrefixNumber { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixInteger
-        /// </summary>
-        [DataMember(Name="prefix_integer", EmitDefaultValue=false)]
-        public int PrefixInteger { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixBoolean
-        /// </summary>
-        [DataMember(Name="prefix_boolean", EmitDefaultValue=false)]
-        public bool PrefixBoolean { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixArray
-        /// </summary>
-        [DataMember(Name="prefix_array", EmitDefaultValue=false)]
-        public List<int> PrefixArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixWrappedArray
-        /// </summary>
-        [DataMember(Name="prefix_wrapped_array", EmitDefaultValue=false)]
-        public List<int> PrefixWrappedArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NamespaceString
-        /// </summary>
-        [DataMember(Name="namespace_string", EmitDefaultValue=false)]
-        public string NamespaceString { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NamespaceNumber
-        /// </summary>
-        [DataMember(Name="namespace_number", EmitDefaultValue=false)]
-        public decimal NamespaceNumber { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NamespaceInteger
-        /// </summary>
-        [DataMember(Name="namespace_integer", EmitDefaultValue=false)]
-        public int NamespaceInteger { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NamespaceBoolean
-        /// </summary>
-        [DataMember(Name="namespace_boolean", EmitDefaultValue=false)]
-        public bool NamespaceBoolean { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NamespaceArray
-        /// </summary>
-        [DataMember(Name="namespace_array", EmitDefaultValue=false)]
-        public List<int> NamespaceArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets NamespaceWrappedArray
-        /// </summary>
-        [DataMember(Name="namespace_wrapped_array", EmitDefaultValue=false)]
-        public List<int> NamespaceWrappedArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNsString
-        /// </summary>
-        [DataMember(Name="prefix_ns_string", EmitDefaultValue=false)]
-        public string PrefixNsString { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNsNumber
-        /// </summary>
-        [DataMember(Name="prefix_ns_number", EmitDefaultValue=false)]
-        public decimal PrefixNsNumber { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNsInteger
-        /// </summary>
-        [DataMember(Name="prefix_ns_integer", EmitDefaultValue=false)]
-        public int PrefixNsInteger { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNsBoolean
-        /// </summary>
-        [DataMember(Name="prefix_ns_boolean", EmitDefaultValue=false)]
-        public bool PrefixNsBoolean { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNsArray
-        /// </summary>
-        [DataMember(Name="prefix_ns_array", EmitDefaultValue=false)]
-        public List<int> PrefixNsArray { get; set; }
-
-        /// <summary>
-        /// Gets or Sets PrefixNsWrappedArray
-        /// </summary>
-        [DataMember(Name="prefix_ns_wrapped_array", EmitDefaultValue=false)]
-        public List<int> PrefixNsWrappedArray { get; set; }
-
-        /// <summary>
-        /// Returns the string presentation of the object
-        /// </summary>
-        /// <returns>String presentation of the object</returns>
-        public override string ToString()
-        {
-            var sb = new StringBuilder();
-            sb.Append("class XmlItem {\n");
-            sb.Append("  AttributeString: ").Append(AttributeString).Append("\n");
-            sb.Append("  AttributeNumber: ").Append(AttributeNumber).Append("\n");
-            sb.Append("  AttributeInteger: ").Append(AttributeInteger).Append("\n");
-            sb.Append("  AttributeBoolean: ").Append(AttributeBoolean).Append("\n");
-            sb.Append("  WrappedArray: ").Append(WrappedArray).Append("\n");
-            sb.Append("  NameString: ").Append(NameString).Append("\n");
-            sb.Append("  NameNumber: ").Append(NameNumber).Append("\n");
-            sb.Append("  NameInteger: ").Append(NameInteger).Append("\n");
-            sb.Append("  NameBoolean: ").Append(NameBoolean).Append("\n");
-            sb.Append("  NameArray: ").Append(NameArray).Append("\n");
-            sb.Append("  NameWrappedArray: ").Append(NameWrappedArray).Append("\n");
-            sb.Append("  PrefixString: ").Append(PrefixString).Append("\n");
-            sb.Append("  PrefixNumber: ").Append(PrefixNumber).Append("\n");
-            sb.Append("  PrefixInteger: ").Append(PrefixInteger).Append("\n");
-            sb.Append("  PrefixBoolean: ").Append(PrefixBoolean).Append("\n");
-            sb.Append("  PrefixArray: ").Append(PrefixArray).Append("\n");
-            sb.Append("  PrefixWrappedArray: ").Append(PrefixWrappedArray).Append("\n");
-            sb.Append("  NamespaceString: ").Append(NamespaceString).Append("\n");
-            sb.Append("  NamespaceNumber: ").Append(NamespaceNumber).Append("\n");
-            sb.Append("  NamespaceInteger: ").Append(NamespaceInteger).Append("\n");
-            sb.Append("  NamespaceBoolean: ").Append(NamespaceBoolean).Append("\n");
-            sb.Append("  NamespaceArray: ").Append(NamespaceArray).Append("\n");
-            sb.Append("  NamespaceWrappedArray: ").Append(NamespaceWrappedArray).Append("\n");
-            sb.Append("  PrefixNsString: ").Append(PrefixNsString).Append("\n");
-            sb.Append("  PrefixNsNumber: ").Append(PrefixNsNumber).Append("\n");
-            sb.Append("  PrefixNsInteger: ").Append(PrefixNsInteger).Append("\n");
-            sb.Append("  PrefixNsBoolean: ").Append(PrefixNsBoolean).Append("\n");
-            sb.Append("  PrefixNsArray: ").Append(PrefixNsArray).Append("\n");
-            sb.Append("  PrefixNsWrappedArray: ").Append(PrefixNsWrappedArray).Append("\n");
-            sb.Append("}\n");
-            return sb.ToString();
-        }
-  
-        /// <summary>
-        /// Returns the JSON string presentation of the object
-        /// </summary>
-        /// <returns>JSON string presentation of the object</returns>
-        public virtual string ToJson()
-        {
-            return JsonConvert.SerializeObject(this, Formatting.Indented);
-        }
-
-        /// <summary>
-        /// Returns true if objects are equal
-        /// </summary>
-        /// <param name="input">Object to be compared</param>
-        /// <returns>Boolean</returns>
-        public override bool Equals(object input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input as XmlItem).AreEqual;
-        }
-
-        /// <summary>
-        /// Returns true if XmlItem instances are equal
-        /// </summary>
-        /// <param name="input">Instance of XmlItem to be compared</param>
-        /// <returns>Boolean</returns>
-        public bool Equals(XmlItem input)
-        {
-            return OpenAPIClientUtils.compareLogic.Compare(this, input).AreEqual;
-        }
-
-        /// <summary>
-        /// Gets the hash code
-        /// </summary>
-        /// <returns>Hash code</returns>
-        public override int GetHashCode()
-        {
-            unchecked // Overflow is fine, just wrap
-            {
-                int hashCode = 41;
-                if (this.AttributeString != null)
-                    hashCode = hashCode * 59 + this.AttributeString.GetHashCode();
-                hashCode = hashCode * 59 + this.AttributeNumber.GetHashCode();
-                hashCode = hashCode * 59 + this.AttributeInteger.GetHashCode();
-                hashCode = hashCode * 59 + this.AttributeBoolean.GetHashCode();
-                if (this.WrappedArray != null)
-                    hashCode = hashCode * 59 + this.WrappedArray.GetHashCode();
-                if (this.NameString != null)
-                    hashCode = hashCode * 59 + this.NameString.GetHashCode();
-                hashCode = hashCode * 59 + this.NameNumber.GetHashCode();
-                hashCode = hashCode * 59 + this.NameInteger.GetHashCode();
-                hashCode = hashCode * 59 + this.NameBoolean.GetHashCode();
-                if (this.NameArray != null)
-                    hashCode = hashCode * 59 + this.NameArray.GetHashCode();
-                if (this.NameWrappedArray != null)
-                    hashCode = hashCode * 59 + this.NameWrappedArray.GetHashCode();
-                if (this.PrefixString != null)
-                    hashCode = hashCode * 59 + this.PrefixString.GetHashCode();
-                hashCode = hashCode * 59 + this.PrefixNumber.GetHashCode();
-                hashCode = hashCode * 59 + this.PrefixInteger.GetHashCode();
-                hashCode = hashCode * 59 + this.PrefixBoolean.GetHashCode();
-                if (this.PrefixArray != null)
-                    hashCode = hashCode * 59 + this.PrefixArray.GetHashCode();
-                if (this.PrefixWrappedArray != null)
-                    hashCode = hashCode * 59 + this.PrefixWrappedArray.GetHashCode();
-                if (this.NamespaceString != null)
-                    hashCode = hashCode * 59 + this.NamespaceString.GetHashCode();
-                hashCode = hashCode * 59 + this.NamespaceNumber.GetHashCode();
-                hashCode = hashCode * 59 + this.NamespaceInteger.GetHashCode();
-                hashCode = hashCode * 59 + this.NamespaceBoolean.GetHashCode();
-                if (this.NamespaceArray != null)
-                    hashCode = hashCode * 59 + this.NamespaceArray.GetHashCode();
-                if (this.NamespaceWrappedArray != null)
-                    hashCode = hashCode * 59 + this.NamespaceWrappedArray.GetHashCode();
-                if (this.PrefixNsString != null)
-                    hashCode = hashCode * 59 + this.PrefixNsString.GetHashCode();
-                hashCode = hashCode * 59 + this.PrefixNsNumber.GetHashCode();
-                hashCode = hashCode * 59 + this.PrefixNsInteger.GetHashCode();
-                hashCode = hashCode * 59 + this.PrefixNsBoolean.GetHashCode();
-                if (this.PrefixNsArray != null)
-                    hashCode = hashCode * 59 + this.PrefixNsArray.GetHashCode();
-                if (this.PrefixNsWrappedArray != null)
-                    hashCode = hashCode * 59 + this.PrefixNsWrappedArray.GetHashCode();
-                return hashCode;
-            }
-        }
-
-        /// <summary>
-        /// To validate all properties of the instance
-        /// </summary>
-        /// <param name="validationContext">Validation context</param>
-        /// <returns>Validation Result</returns>
-        IEnumerable<System.ComponentModel.DataAnnotations.ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
-        {
-            yield break;
-        }
-    }
-
-}
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Zebra.cs b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Zebra.cs
index dcc669f49d38..3c6a2ce878a2 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Zebra.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Zebra.cs
@@ -66,7 +66,10 @@ public enum TypeEnum
         /// Initializes a new instance of the <see cref="Zebra" /> class.
         /// </summary>
         [JsonConstructorAttribute]
-        protected Zebra() { }
+        protected Zebra()
+        {
+            this.AdditionalProperties = new Dictionary<string, object>();
+        }
         /// <summary>
         /// Initializes a new instance of the <see cref="Zebra" /> class.
         /// </summary>
@@ -77,6 +80,7 @@ protected Zebra() { }
             // to ensure "className" is required (not null)
             this.ClassName = className ?? throw new ArgumentNullException("className is a required property for Zebra and cannot be null");
             this.Type = type;
+            this.AdditionalProperties = new Dictionary<string, object>();
         }
 
         /// <summary>
@@ -85,6 +89,12 @@ protected Zebra() { }
         [DataMember(Name = "className", EmitDefaultValue = false)]
         public string ClassName { get; set; }
 
+        /// <summary>
+        /// Gets or Sets additional properties
+        /// </summary>
+        [JsonExtensionData]
+        public IDictionary<string, object> AdditionalProperties { get; set; }
+
         /// <summary>
         /// Returns the string presentation of the object
         /// </summary>
@@ -96,6 +106,7 @@ public override string ToString()
             sb.Append("  ").Append(base.ToString().Replace("\n", "\n  ")).Append("\n");
             sb.Append("  Type: ").Append(Type).Append("\n");
             sb.Append("  ClassName: ").Append(ClassName).Append("\n");
+            sb.Append("  AdditionalProperties: ").Append(AdditionalProperties).Append("\n");
             sb.Append("}\n");
             return sb.ToString();
         }
@@ -141,6 +152,8 @@ public override int GetHashCode()
                 hashCode = hashCode * 59 + this.Type.GetHashCode();
                 if (this.ClassName != null)
                     hashCode = hashCode * 59 + this.ClassName.GetHashCode();
+                if (this.AdditionalProperties != null)
+                    hashCode = hashCode * 59 + this.AdditionalProperties.GetHashCode();
                 return hashCode;
             }
         }