--- old/src/java.desktop/share/classes/java/awt/event/HierarchyBoundsAdapter.java	2020-08-05 16:55:39.169828000 -0700
+++ new/src/java.desktop/share/classes/java/awt/event/HierarchyBoundsAdapter.java	2020-08-05 16:55:38.573681600 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 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 +50,11 @@
 public abstract class HierarchyBoundsAdapter implements HierarchyBoundsListener
 {
     /**
+     * Constructs a {@code HierarchyBoundsAdapter}.
+     */
+    protected HierarchyBoundsAdapter() {}
+
+    /**
      * Called when an ancestor of the source is moved.
      */
     public void ancestorMoved(HierarchyEvent e) {}