java.lang.IllegalArgumentException: skip value is negative
   at java.io.Reader.skip(Reader.java:161)
   at org.netbeans.api.java.source.ModificationResult.commit(ModificationResult.java:306)
   at org.netbeans.api.java.source.ModificationResult.getResultingSource(ModificationResult.java:452)
   at org.netbeans.modules.refactoring.java.spi.DiffElement.getNewFileContent(DiffElement.java:145)
   at org.netbeans.modules.refactoring.spi.AccessorImpl.getNewFileContent(AccessorImpl.java:82)
   at org.netbeans.modules.refactoring.spi.impl.PreviewManager.refresh(PreviewManager.java:134)
   at org.netbeans.modules.refactoring.spi.SimpleRefactoringElementImplementation.showPreview(SimpleRefactoringElementImplementation.java:133)
   at org.netbeans.modules.refactoring.spi.impl.CheckNodeListener.openDiff(CheckNodeListener.java:296)
   at org.netbeans.modules.refactoring.spi.impl.CheckNodeListener.selectNextPrev(CheckNodeListener.java:330)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.selectNextUsage(RefactoringPanel.java:1028)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel$5.run(RefactoringPanel.java:879)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:646)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:607)
   at java.awt.EventQueue$1.run(EventQueue.java:605)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:616)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158)
   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)