--- old/src/java.desktop/share/classes/java/awt/event/ContainerAdapter.java	2020-08-05 16:55:32.472787800 -0700
+++ new/src/java.desktop/share/classes/java/awt/event/ContainerAdapter.java	2020-08-05 16:55:31.896672900 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -50,6 +50,12 @@
  * @since 1.1
  */
 public abstract class ContainerAdapter implements ContainerListener {
+
+    /**
+     * Constructs a {@code ContainerAdapter}.
+     */
+    protected ContainerAdapter() {}
+
     /**
      * Invoked when a component has been added to the container.
      */