java.lang.IllegalArgumentException: java.lang.ClassCastException@6ac08f22
   at sun.reflect.GeneratedMethodAccessor152.invoke(GeneratedMethodAccessor152.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:497)
   at org.openide.util.WeakListenerImpl$ListenerReference.run(WeakListenerImpl.java:638)
   at org.openide.util.lookup.implspi.ActiveQueue$Daemon.run(ActiveQueue.java:192)