--- a/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java	Thu Oct 17 07:31:35 2019 +0800
+++ b/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java	Wed Oct 16 16:55:52 2019 -0700
@@ -4584,6 +4584,7 @@
     public static class KeySetView<K,V> extends CollectionView<K,V,K>
         implements Set<K>, java.io.Serializable {
         private static final long serialVersionUID = 7249069246763182397L;
+        @SuppressWarnings("serial") // Conditionally serializable
         private final V value;
         KeySetView(ConcurrentHashMap<K,V> map, V value) {  // non-public
             super(map);