copyright header

Author: jeysal

packages/jest-util/src/isPromise.ts

@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
 // see ES2015 spec 25.4.4.5, https://stackoverflow.com/a/38339199
 const isPromise = (candidate: unknown): candidate is Promise<unknown> =>
   Promise.resolve(candidate) === candidate;