From 709cbfd60f7a7497004a59eeeaaff220a9f5e8b1 Mon Sep 17 00:00:00 2001
From: Andrea Lin <asdf.lina@gmail.com>
Date: Fri, 22 Feb 2019 10:10:49 -0800
Subject: [PATCH 1/2] add builder methods to EmptyMessage

---
 .../google/api/gax/httpjson/EmptyMessage.java | 59 +++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java
index f2badaed2..6871daf74 100644
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java
+++ b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java
@@ -30,6 +30,7 @@
 package com.google.api.gax.httpjson;
 
 import java.util.List;
+import java.util.Objects;
 import javax.annotation.Nullable;
 
 /**
@@ -58,4 +59,62 @@ public List<String> getFieldMask() {
   public ApiMessage getApiMessageRequestBody() {
     return null;
   }
+
+  @Override
+  public boolean equals(Object other) {
+    return other instanceof EmptyMessage;
+  }
+
+  private static final EmptyMessage DEFAULT_INSTANCE;
+
+  public static EmptyMessage getDefaultInstance() {
+    return DEFAULT_INSTANCE;
+  }
+
+  private EmptyMessage() {}
+
+  public static Builder newBuilder() {
+    return DEFAULT_INSTANCE.toBuilder();
+  }
+
+  public static Builder newBuilder(EmptyMessage prototype) {
+    return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
+  }
+
+  public Builder toBuilder() {
+    return this == DEFAULT_INSTANCE ? new Builder() : new Builder().mergeFrom(this);
+  }
+
+  static {
+    DEFAULT_INSTANCE = new EmptyMessage();
+  }
+
+  public static class Builder {
+    Builder() {}
+
+    public Builder mergeFrom(EmptyMessage other) {
+      return this;
+    }
+
+    public Builder(EmptyMessage other) {}
+
+    public EmptyMessage build() {
+      return new EmptyMessage();
+    }
+
+    public Builder clone() {
+      Builder newBuilder = new Builder();
+      return newBuilder;
+    }
+  }
+
+  @Override
+  public String toString() {
+    return "EmptyMessage{}";
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(DEFAULT_INSTANCE);
+  }
 }

From 42d0c1d329e0a0b5cde677dd0c37383c61981ad8 Mon Sep 17 00:00:00 2001
From: Andrea Lin <asdf.lina@gmail.com>
Date: Thu, 28 Feb 2019 10:39:31 -0800
Subject: [PATCH 2/2] made EmptyMessage a singleton

---
 .../com/google/api/gax/httpjson/EmptyMessage.java    | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java
index 6871daf74..393332d01 100644
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java
+++ b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/EmptyMessage.java
@@ -65,7 +65,8 @@ public boolean equals(Object other) {
     return other instanceof EmptyMessage;
   }
 
-  private static final EmptyMessage DEFAULT_INSTANCE;
+  // This is a singleton class.
+  private static final EmptyMessage DEFAULT_INSTANCE = new EmptyMessage();
 
   public static EmptyMessage getDefaultInstance() {
     return DEFAULT_INSTANCE;
@@ -85,10 +86,6 @@ public Builder toBuilder() {
     return this == DEFAULT_INSTANCE ? new Builder() : new Builder().mergeFrom(this);
   }
 
-  static {
-    DEFAULT_INSTANCE = new EmptyMessage();
-  }
-
   public static class Builder {
     Builder() {}
 
@@ -99,12 +96,11 @@ public Builder mergeFrom(EmptyMessage other) {
     public Builder(EmptyMessage other) {}
 
     public EmptyMessage build() {
-      return new EmptyMessage();
+      return DEFAULT_INSTANCE;
     }
 
     public Builder clone() {
-      Builder newBuilder = new Builder();
-      return newBuilder;
+      return new Builder();
     }
   }