java.lang.NullPointerException
   at org.netbeans.modules.java.hints.introduce.Flow$State.merge(Flow.java:535)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.mergeOr(Flow.java:510)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.visitIf(Flow.java:270)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.visitIf(Flow.java:137)
   at com.sun.tools.javac.tree.JCTree$JCIf.accept(JCTree.java:1153)
   at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:67)
   at org.netbeans.api.java.source.support.CancellableTreePathScanner.scan(CancellableTreePathScanner.java:94)
   at com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:80)
   at com.sun.source.util.TreeScanner.scan(TreeScanner.java:90)
   at org.netbeans.api.java.source.support.CancellableTreePathScanner.scan(CancellableTreePathScanner.java:103)
   at com.sun.source.util.TreeScanner.visitBlock(TreeScanner.java:159)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:795)
   at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:67)
   at org.netbeans.api.java.source.support.CancellableTreePathScanner.scan(CancellableTreePathScanner.java:94)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.visitWhileLoop(Flow.java:437)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.visitWhileLoop(Flow.java:137)
   at com.sun.tools.javac.tree.JCTree$JCWhileLoop.accept(JCTree.java:849)
   at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:67)
   at org.netbeans.api.java.source.support.CancellableTreePathScanner.scan(CancellableTreePathScanner.java:94)
   at com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:80)
   at com.sun.source.util.TreeScanner.scan(TreeScanner.java:90)
   at org.netbeans.api.java.source.support.CancellableTreePathScanner.scan(CancellableTreePathScanner.java:103)
   at com.sun.source.util.TreeScanner.visitBlock(TreeScanner.java:159)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:795)
   at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:67)
   at org.netbeans.api.java.source.support.CancellableTreePathScanner.scan(CancellableTreePathScanner.java:94)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.visitMethod(Flow.java:409)
   at org.netbeans.modules.java.hints.introduce.Flow$VisitorImpl.visitMethod(Flow.java:137)
   at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:695)
   at com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:49)
   at org.netbeans.modules.java.hints.introduce.Flow.assignmentsForUse(Flow.java:93)
   at org.netbeans.modules.java.hints.introduce.IntroduceHint.computeIntroduceMethod(IntroduceHint.java:568)
   at org.netbeans.modules.java.hints.introduce.IntroduceHint.computeError(IntroduceHint.java:518)
   at org.netbeans.modules.java.hints.introduce.IntroduceHint.run(IntroduceHint.java:354)
   at org.netbeans.modules.java.hints.introduce.IntroduceHint.run(IntroduceHint.java:152)
   at org.netbeans.modules.java.source.JavaSourceAccessor$CancelableTaskWrapper.run(JavaSourceAccessor.java:322)
   at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:676)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
   at java.util.concurrent.FutureTask.run(FutureTask.java:166)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
   at java.lang.Thread.run(Thread.java:722)