org.netbeans.editor.GuardedException: Attempt to insert into guarded block at position 1,242.
        at org.netbeans.editor.GuardedDocument.preInsertCheck(GuardedDocument.java:221)
        at org.netbeans.editor.BaseDocument.insertString(BaseDocument.java:728)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator$.run(AddPropertyCodeGenerator.java:155)
        at org.netbeans.editor.GuardedDocument.runAtomicAsUser(GuardedDocument.java:324)
        at org.openide.text.NbDocument.runAtomicAsUser(NbDocument.java:410)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator.insertCodeImpl(AddPropertyCodeGenerator.java:149)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator$.run(AddPropertyCodeGenerator.java:133)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator$.run(AddPropertyCodeGenerator.java:132)
        at org.netbeans.api.java.source.JavaSource.runUserActionTaskImpl(JavaSource.java:680)
        at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:607)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator.insertCode(AddPropertyCodeGenerator.java:131)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator.perform(AddPropertyCodeGenerator.java:125)
        at org.netbeans.modules.beans.addproperty.AddPropertyCodeGenerator.invoke(AddPropertyCodeGenerator.java:114)
        at org.netbeans.modules.editor.codegen.GenerateCodePanel.invokeSelected(GenerateCodePanel.java:148)
        at org.netbeans.modules.editor.codegen.GenerateCodePanel.listMouseReleased(GenerateCodePanel.java:117)
        at org.netbeans.modules.editor.codegen.GenerateCodePanel.access$100(GenerateCodePanel.java:60)
        at org.netbeans.modules.editor.codegen.GenerateCodePanel$.mouseReleased(GenerateCodePanel.java:103)
        at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:273)
        at java.awt.Component.processMouseEvent(Component.java:6134)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
        at java.awt.Component.processEvent(Component.java:5899)
        at java.awt.Container.processEvent(Container.java:2023)
        at java.awt.Component.dispatchEventImpl(Component.java:4501)
        at java.awt.Container.dispatchEventImpl(Container.java:2081)
        at java.awt.Component.dispatchEvent(Component.java:4331)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4301)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3965)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3895)
        at java.awt.Container.dispatchEventImpl(Container.java:2067)
        at java.awt.Window.dispatchEventImpl(Window.java:2458)
        at java.awt.Component.dispatchEvent(Component.java:4331)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        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)