--- a/src/java.base/share/classes/java/util/HashSet.java	Thu Jun 13 16:39:20 2019 -0700
+++ b/src/java.base/share/classes/java/util/HashSet.java	Fri Jun 14 05:02:58 2019 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2019, 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
@@ -358,4 +358,14 @@
     public Spliterator<E> spliterator() {
         return new HashMap.KeySpliterator<>(map, 0, -1, 0, 0);
     }
+
+    @Override
+    public Object[] toArray() {
+        return map.keysToArray(new Object[map.size()]);
+    }
+
+    @Override
+    public <T> T[] toArray(T[] a) {
+        return map.keysToArray(map.prepareArray(a));
+    }
 }