java.lang.OutOfMemoryError: Java heap space
   at java.util.Arrays.copyOfRange(Arrays.java:2694)
   at java.lang.String.<init>(String.java:203)
   at java.lang.StringBuilder.toString(StringBuilder.java:405)
   at org.netbeans.modules.editor.lib2.document.ContentEdit.toString(ContentEdit.java:198)
   at java.lang.String.valueOf(String.java:2854)
   at java.lang.StringBuilder.append(StringBuilder.java:128)
   at java.util.AbstractCollection.toString(AbstractCollection.java:450)
   at java.util.Vector.toString(Vector.java:996)
   at javax.swing.text.AbstractDocument$DefaultDocumentEvent.toString(AbstractDocument.java:2731)
   at org.netbeans.editor.BaseDocumentEvent.toString(BaseDocumentEvent.java:588)
   at java.lang.String.valueOf(String.java:2854)
   at java.lang.StringBuilder.append(StringBuilder.java:128)
   at org.netbeans.modules.editor.lib2.view.ViewUpdates.incomingEvent(ViewUpdates.java:531)
   at org.netbeans.modules.editor.lib2.view.ViewUpdates$IncomingModificationListener.removeUpdate(ViewUpdates.java:584)
   at sun.reflect.GeneratedMethodAccessor61.invoke(GeneratedMethodAccessor61.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:601)
   at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:458)
   at com.sun.proxy.$Proxy21.removeUpdate(.java:0)
   at org.netbeans.lib.editor.util.swing.PriorityDocumentListenerList.removeUpdate(PriorityDocumentListenerList.java:116)
   at javax.swing.text.AbstractDocument.fireRemoveUpdate(AbstractDocument.java:260)
   at org.netbeans.editor.BaseDocument.fireRemoveUpdate(BaseDocument.java:1627)
   at org.netbeans.editor.BaseDocumentEvent.undo(BaseDocumentEvent.java:288)
   at org.netbeans.editor.GuardedDocumentEvent.undo(GuardedDocumentEvent.java:72)
   at org.netbeans.modules.editor.lib2.document.StableCompoundEdit.undo(StableCompoundEdit.java:93)
   at org.netbeans.editor.BaseDocument$AtomicCompoundEdit.undo(BaseDocument.java:2196)
   at org.netbeans.editor.BaseDocument.undoAtomicEdits(BaseDocument.java:2114)
   at org.netbeans.editor.BaseDocument.breakAtomicLock(BaseDocument.java:1800)
   at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:327)
   at org.openide.text.NbDocument.runAtomic(NbDocument.java:436)
   at org.openide.text.DocumentOpenClose$DocumentLoad.run(DocumentOpenClose.java:663)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432)