org.netbeans.editor.GuardedException: Attempt to remove from guarded block at position 4.021.
   at org.netbeans.editor.GuardedDocument.preRemoveCheck(GuardedDocument.java:291)
   at org.netbeans.editor.BaseDocument.handleRemove(BaseDocument.java:925)
   at org.netbeans.editor.BaseDocument$FilterBypassImpl.remove(BaseDocument.java:2343)
   at javax.swing.text.DocumentFilter.remove(DocumentFilter.java:51)
   at org.openide.text.CloneableEditorSupport$DocFilter.remove(CloneableEditorSupport.java:2997)
   at org.netbeans.editor.BaseDocument.remove(BaseDocument.java:889)
   at org.netbeans.api.java.source.ModificationResult.processDocumentLocked(ModificationResult.java:406)
   at org.netbeans.api.java.source.ModificationResult.access$100(ModificationResult.java:95)
   at org.netbeans.api.java.source.ModificationResult$3.run(ModificationResult.java:371)
   at org.netbeans.editor.GuardedDocument.runAtomicAsUser(GuardedDocument.java:347)
   at org.openide.text.NbDocument.runAtomicAsUser(NbDocument.java:448)
Caused: java.io.IOException
   at org.netbeans.api.java.source.ModificationResult.processDocument(ModificationResult.java:391)
   at org.netbeans.api.java.source.ModificationResult.commit2(ModificationResult.java:333)
   at org.netbeans.api.java.source.ModificationResult.access$000(ModificationResult.java:95)
   at org.netbeans.api.java.source.ModificationResult$2.run(ModificationResult.java:241)
   at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:317)
   at org.openide.text.NbDocument.runAtomic(NbDocument.java:422)
   at org.netbeans.api.java.source.ModificationResult.commit(ModificationResult.java:238)
   at org.netbeans.api.java.source.ModificationResult.commit(ModificationResult.java:201)
   at org.netbeans.modules.java.hints.introduce.IntroduceHint$IntroduceFix.implement(IntroduceHint.java:1416)
   at org.netbeans.modules.java.hints.introduce.MethodCandidateChooser.openSelected(MethodCandidateChooser.java:197)
   at org.netbeans.modules.java.hints.introduce.MethodCandidateChooser.jList1MouseClicked(MethodCandidateChooser.java:172)
   at org.netbeans.modules.java.hints.introduce.MethodCandidateChooser.access$200(MethodCandidateChooser.java:72)
   at org.netbeans.modules.java.hints.introduce.MethodCandidateChooser$3.mouseClicked(MethodCandidateChooser.java:150)
   at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:253)
   at java.awt.Component.processMouseEvent(Component.java:6291)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
   at java.awt.Component.processEvent(Component.java:6053)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4651)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4577)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4247)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4168)
   at java.awt.Container.dispatchEventImpl(Container.java:2085)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:602)
   at java.awt.EventQueue$1.run(EventQueue.java:600)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
   at java.awt.EventQueue$2.run(EventQueue.java:616)
   at java.awt.EventQueue$2.run(EventQueue.java:614)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:162)
   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)