java.lang.NullPointerException
   at com.sun.tools.javac.comp.Attr.check(Attr.java:231)
   at com.sun.tools.javac.comp.Attr.visitLambda(Attr.java:2610)
   at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1777)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.visitLambda(Attr.java:2621)
   at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1777)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.DeferredAttr$4.complete(DeferredAttr.java:341)
   at com.sun.tools.javac.comp.ArgumentAttr$ArgumentType.complete(ArgumentAttr.java:361)
   at com.sun.tools.javac.comp.DeferredAttr$DeferredType.check(DeferredAttr.java:302)
   at com.sun.tools.javac.comp.DeferredAttr$DeferredType.check(DeferredAttr.java:289)
   at com.sun.tools.javac.comp.Resolve$MethodResultInfo.check(Resolve.java:1021)
   at com.sun.tools.javac.comp.Resolve$4.checkArg(Resolve.java:843)
   at com.sun.tools.javac.comp.Resolve$AbstractMethodCheck.argumentsAcceptable(Resolve.java:748)
   at com.sun.tools.javac.comp.Resolve$4.argumentsAcceptable(Resolve.java:852)
   at com.sun.tools.javac.comp.Resolve.rawInstantiate(Resolve.java:592)
   at com.sun.tools.javac.comp.Resolve.checkMethod(Resolve.java:618)
   at com.sun.tools.javac.comp.Attr.checkMethod(Attr.java:4157)
   at com.sun.tools.javac.comp.Attr.checkIdInternal(Attr.java:3943)
   at com.sun.tools.javac.comp.Attr.checkMethodIdInternal(Attr.java:3850)
   at com.sun.tools.javac.comp.Attr.checkMethodId(Attr.java:3829)
   at com.sun.tools.javac.comp.Attr.checkId(Attr.java:3816)
   at com.sun.tools.javac.comp.Attr.visitSelect(Attr.java:3701)
   at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:2075)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.visitApply(Attr.java:1925)
   at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1604)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:681)
   at com.sun.tools.javac.comp.Attr.visitExec(Attr.java:1684)
   at com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1422)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:705)
   at com.sun.tools.javac.comp.Attr.attribStats(Attr.java:729)
   at com.sun.tools.javac.comp.Attr.visitBlock(Attr.java:1201)
   at org.netbeans.lib.nbjavac.services.NBAttr.visitBlock(NBAttr.java:82)
   at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:990)
   at com.sun.tools.javac.comp.Attr$ResultInfo.attr(Attr.java:494)
   at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:635)
   at com.sun.tools.javac.comp.Attr.attribStat(Attr.java:705)
   at com.sun.tools.javac.comp.Attr.attribStatToTree(Attr.java:412)
   at com.sun.tools.javac.api.JavacTrees.attribStatToTree(JavacTrees.java:975)
   at com.sun.tools.javac.api.JavacTrees.getAttrContext(JavacTrees.java:935)
   at com.sun.tools.javac.api.JavacTrees.getScope(JavacTrees.java:794)
   at com.sun.tools.javac.api.JavacTrees.getScope(JavacTrees.java:156)
   at org.netbeans.modules.refactoring.java.RefactoringUtils.variableClashes(RefactoringUtils.java:968)
   at org.netbeans.modules.refactoring.java.plugins.RenameRefactoringPlugin.fastCheckParameters(RenameRefactoringPlugin.java:358)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:408)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:378)
   at org.netbeans.api.java.source.JavaSource$MultiTask.run(JavaSource.java:486)
   at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:609)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:153)
   at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:137)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:204)
   at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:201)
   at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:176)
   at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360)
   at org.netbeans.modules.parsing.nb.DataObjectEnvFactory.runPriorityIO(DataObjectEnvFactory.java:141)
   at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:88)
   at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:201)
   at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:104)
   at org.netbeans.api.java.source.JavaSource.runUserActionTaskImpl(JavaSource.java:436)
   at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:407)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.run(JavaRefactoringPlugin.java:391)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin$WorkingTask.access$100(JavaRefactoringPlugin.java:378)
   at org.netbeans.modules.refactoring.java.spi.JavaRefactoringPlugin.fastCheckParameters(JavaRefactoringPlugin.java:150)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.pluginsFastCheckParams(AbstractRefactoring.java:535)
   at org.netbeans.modules.refactoring.api.AbstractRefactoring.fastCheckParameters(AbstractRefactoring.java:288)
   at org.netbeans.modules.refactoring.java.ui.RenameRefactoringUI.checkParameters(RenameRefactoringUI.java:268)
   at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.stateChanged(ParametersPanel.java:972)
   at org.netbeans.modules.refactoring.java.ui.RenamePanel.nameFieldFocusLost(RenamePanel.java:465)
   at org.netbeans.modules.refactoring.java.ui.RenamePanel.access$800(RenamePanel.java:88)
   at org.netbeans.modules.refactoring.java.ui.RenamePanel$5.focusLost(RenamePanel.java:336)
   at java.awt.AWTEventMulticaster.focusLost(AWTEventMulticaster.java:230)
   at java.awt.Component.processFocusEvent(Component.java:6417)
   at java.awt.Component.processEvent(Component.java:6281)
   at java.awt.Container.processEvent(Container.java:2234)
   at java.awt.Component.dispatchEventImpl(Component.java:4881)
   at java.awt.Container.dispatchEventImpl(Container.java:2292)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1954)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:995)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:661)
   at java.awt.Component.dispatchEventImpl(Component.java:4752)
   at java.awt.Container.dispatchEventImpl(Container.java:2292)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.SentEvent.dispatch(SentEvent.java:70)
   at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:217)
   at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:244)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:731)
   at java.awt.Component.dispatchEventImpl(Component.java:4752)
   at java.awt.Container.dispatchEventImpl(Container.java:2292)
   at java.awt.Window.dispatchEventImpl(Window.java:2750)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.SequencedEvent.dispatch(SequencedEvent.java:128)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
   at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
   at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
   at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
   at java.awt.Dialog.show(Dialog.java:1084)
   at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:1065)
   at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1115)
   at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:1087)
   at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:128)
   at org.netbeans.modules.openide.util.NbMutexEventProvider$Event.doEventAccess(NbMutexEventProvider.java:138)
   at org.netbeans.modules.openide.util.NbMutexEventProvider$Event.readAccess(NbMutexEventProvider.java:98)
   at org.netbeans.modules.openide.util.LazyMutexImplementation.readAccess(LazyMutexImplementation.java:94)
   at org.openide.util.Mutex.readAccess(Mutex.java:218)
   at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:1072)
   at java.awt.Component.show(Component.java:1654)
   at java.awt.Component.setVisible(Component.java:1606)
   at java.awt.Window.setVisible(Window.java:1014)
   at java.awt.Dialog.setVisible(Dialog.java:1005)
   at org.netbeans.core.NotifyExcPanel.updateState(NotifyExcPanel.java:427)
   at org.netbeans.core.NotifyExcPanel.access$300(NotifyExcPanel.java:105)
   at org.netbeans.core.NotifyExcPanel$2.run(NotifyExcPanel.java:357)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
   at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
   at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
   at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
   at java.awt.Dialog.show(Dialog.java:1084)
   at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:1065)
   at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1115)
   at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:1087)
   at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:128)
   at org.netbeans.modules.openide.util.NbMutexEventProvider$Event.doEventAccess(NbMutexEventProvider.java:138)
   at org.netbeans.modules.openide.util.NbMutexEventProvider$Event.readAccess(NbMutexEventProvider.java:98)
   at org.netbeans.modules.openide.util.LazyMutexImplementation.readAccess(LazyMutexImplementation.java:94)
   at org.openide.util.Mutex.readAccess(Mutex.java:218)
   at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:1072)
   at java.awt.Component.show(Component.java:1654)
   at java.awt.Component.setVisible(Component.java:1606)
   at java.awt.Window.setVisible(Window.java:1014)
   at java.awt.Dialog.setVisible(Dialog.java:1005)
   at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.showDialog(ParametersPanel.java:685)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.refresh(RefactoringPanel.java:685)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.<init>(RefactoringPanel.java:169)
   at org.netbeans.modules.refactoring.spi.ui.UI.openRefactoringUI(UI.java:86)
   at org.netbeans.modules.refactoring.java.ui.ContextAnalyzer$4.show(ContextAnalyzer.java:671)
   at org.netbeans.modules.refactoring.java.ui.ContextAnalyzer$TextComponentTask.run(ContextAnalyzer.java:392)
   at org.netbeans.api.java.source.ui.ScanDialog.runWhenScanFinished(ScanDialog.java:153)
   at org.netbeans.modules.refactoring.java.ui.RefactoringActionsProvider.doFullRename(RefactoringActionsProvider.java:154)
   at org.netbeans.modules.refactoring.java.ui.RefactoringActionsProvider.doRename(RefactoringActionsProvider.java:101)
   at org.netbeans.modules.refactoring.api.impl.ActionsImplementationFactory.doRename(ActionsImplementationFactory.java:91)
   at org.netbeans.modules.refactoring.spi.impl.RenameAction.performAction(RenameAction.java:77)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringGlobalAction.performAction(RefactoringGlobalAction.java:140)
   at org.openide.util.actions.NodeAction.performAction(NodeAction.java:295)
   at org.openide.util.actions.CallableSystemAction$1.run(CallableSystemAction.java:130)
   at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:95)
   at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:116)
   at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99)
   at org.openide.util.actions.CallableSystemAction.actionPerformed(CallableSystemAction.java:127)
   at org.openide.util.actions.NodeAction.actionPerformed(NodeAction.java:283)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
   at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
   at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
   at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
   at javax.swing.AbstractButton.doClick(AbstractButton.java:376)
   at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833)
   at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877)
   at java.awt.Component.processMouseEvent(Component.java:6525)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
   at java.awt.Component.processEvent(Component.java:6290)
   at java.awt.Container.processEvent(Container.java:2234)
   at java.awt.Component.dispatchEventImpl(Component.java:4881)
   at java.awt.Container.dispatchEventImpl(Container.java:2292)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4898)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4533)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4462)
   at java.awt.Container.dispatchEventImpl(Container.java:2278)
   at java.awt.Window.dispatchEventImpl(Window.java:2750)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)