src/share/classes/javax/swing/tree/TreeNode.java

@@ -97,7 +97,7 @@
     /**
      * Returns the children of the receiver as an <code>Enumeration</code>.
      *
      * @return              the children of the receiver as an {@code Enumeration}
      */
-    Enumeration<TreeNode> children();
+    Enumeration<? extends TreeNode> children();
 }