java.lang.NullPointerException
        at org.netbeans.modules.java.source.save.CasualDiff.diffBreak(CasualDiff.java:1065)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2684)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:3115)
        at org.netbeans.modules.java.source.save.CasualDiff.diffIf(CasualDiff.java:1029)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2678)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffList(CasualDiff.java:2371)
        at org.netbeans.modules.java.source.save.CasualDiff.diffBlock(CasualDiff.java:784)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2642)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:3115)
        at org.netbeans.modules.java.source.save.CasualDiff.diffForLoop(CasualDiff.java:860)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2651)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffList(CasualDiff.java:2333)
        at org.netbeans.modules.java.source.save.CasualDiff.diffBlock(CasualDiff.java:784)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2642)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffMethodDef(CasualDiff.java:630)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2633)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffList(CasualDiff.java:2333)
        at org.netbeans.modules.java.source.save.CasualDiff.diffClassDef(CasualDiff.java:467)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2630)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2571)
        at org.netbeans.modules.java.source.save.CasualDiff.diffList(CasualDiff.java:2355)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTopLevel(CasualDiff.java:273)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTreeImpl(CasualDiff.java:2624)
        at org.netbeans.modules.java.source.save.CasualDiff.diffTree(CasualDiff.java:2583)
        at org.netbeans.modules.java.source.save.CasualDiff.diff(CasualDiff.java:191)
        at org.netbeans.api.java.source.WorkingCopy.processCurrentCompilationUnit(WorkingCopy.java:444)
        at org.netbeans.api.java.source.WorkingCopy.getChanges(WorkingCopy.java:505)
        at org.netbeans.api.java.source.JavaSource$1.run(JavaSource.java:651)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:129)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:113)
        at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:189)
        at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:99)
        at org.netbeans.api.java.source.JavaSource.runModificationTask(JavaSource.java:663)
        at org.netbeans.modules.java.hints.introduce.IntroduceHint$IntroduceMethodFix.implement(IntroduceHint.java:1666)
        at org.netbeans.modules.editor.hints.HintsUI$1.run(HintsUI.java:589)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:577)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1030)