--- old/src/java.base/share/classes/javax/net/ssl/HandshakeCompletedEvent.java	2019-08-27 17:29:20.850324386 -0700
+++ new/src/java.base/share/classes/javax/net/ssl/HandshakeCompletedEvent.java	2019-08-27 17:29:20.686324386 -0700
@@ -49,6 +49,7 @@
  */
 public class HandshakeCompletedEvent extends EventObject
 {
+    @java.io.Serial
     private static final long serialVersionUID = 7914963744257769778L;
 
     private transient SSLSession session;