--- old/src/java.desktop/share/classes/java/awt/desktop/FilesEvent.java	2018-12-04 16:22:31.000000000 -0800
+++ new/src/java.desktop/share/classes/java/awt/desktop/FilesEvent.java	2018-12-04 16:22:30.000000000 -0800
@@ -39,7 +39,14 @@
  */
 public class FilesEvent extends AppEvent {
 
+    /**
+     * Use serialVersionUID from JDK 9 for interoperability.
+     */
     private static final long serialVersionUID = 5271763715462312871L;
+
+    /**
+     * The list of files.
+     */
     final List<File> files;
 
     /**