Add comment to warn about calling class name nullability

Reviewed By: oprisnik

Differential Revision: D58649854

fbshipit-source-id: 42dea7f5a39e44a3a18fd0a156737f0aa47c4943

fbcore/src/main/java/com/facebook/common/callercontext/ImageAttribution.java

@@ -1,4 +1,9 @@
-// (c) Meta Platforms, Inc. and affiliates. Confidential and proprietary.
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
 
 package com.facebook.common.callercontext;
 
@@ -8,6 +13,10 @@
 @Nullsafe(Nullsafe.Mode.LOCAL)
 public interface ImageAttribution {
 
+ /**
+ * In production, this often returns a null value. Keep that in mind when using this. See
+ * T192655206 for example.
+ */
  String getCallingClassName();
 
  @Nullable