java.lang.AssertionError: visnodes.size()=0 snapshot.size()=1
        at org.openide.explorer.view.VisualizerChildren.recomputeIndexes(VisualizerChildren.java:87)
        at org.openide.explorer.view.VisualizerChildren.removed(VisualizerChildren.java:264)
        at org.openide.explorer.view.VisualizerEvent$Removed.run(VisualizerEvent.java:132)
        at org.openide.util.Mutex.readAccess(Mutex.java:362)
        at org.openide.explorer.view.VisualizerNode$QP.run(VisualizerNode.java:708)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)