--- old/src/java.base/share/classes/java/util/concurrent/ConcurrentSkipListSet.java	2019-10-14 17:26:56.198013899 -0700
+++ new/src/java.base/share/classes/java/util/concurrent/ConcurrentSkipListSet.java	2019-10-14 17:26:56.010013899 -0700
@@ -103,6 +103,7 @@
      * element.  This field is declared final for the sake of thread
      * safety, which entails some ugliness in clone().
      */
+    @SuppressWarnings("serial") // Conditionally serializable
     private final ConcurrentNavigableMap<E,Object> m;
 
     /**