Error when executing the testCAforIncludeTaglibInInenerNodes VPE JUnit test

Sometimes, the VpeController.notifyChanged method is called when the VPE is disposed. This causes NPE.
The solution is to check if the editor is disposed and, if it is,.not to execute the method.
This error occurs randomly.

Stack trace:

Failed to execute runnable (java.lang.NullPointerException)

org.eclipse.swt.SWTException: Failed to execute runnable (java.lang.NullPointerException)
at org.eclipse.swt.SWT.error(SWT.java:3563)
at org.eclipse.swt.SWT.error(SWT.java:3481)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3296)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2974)
at org.jboss.tools.vpe.ui.test.TestUtil.delay(TestUtil.java:144)
at org.jboss.tools.jsf.vpe.jsf.test.jbide.JBIDE788Test.baseCheckofCA(JBIDE788Test.java:243)
at org.jboss.tools.jsf.vpe.jsf.test.jbide.JBIDE788Test.testCAforIncludeTaglibInInenerNodes(JBIDE788Test.java:56)
at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
at junit.extensions.TestSetup$1.protect(TestSetup.java:21)
at junit.extensions.TestSetup.run(TestSetup.java:25)
at org.eclipse.test.EclipseTestRunner.run(EclipseTestRunner.java:354)
at org.eclipse.test.EclipseTestRunner.run(EclipseTestRunner.java:206)
at org.eclipse.test.UITestApplication$3.run(UITestApplication.java:195)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:129)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3296)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2974)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
at org.eclipse.test.UITestApplication.runApplication(UITestApplication.java:138)
at org.eclipse.test.UITestApplication.run(UITestApplication.java:60)
at org.eclipse.test.UITestApplication.start(UITestApplication.java:210)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:508)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447)
at org.eclipse.equinox.launcher.Main.run(Main.java:1173)
at org.eclipse.equinox.launcher.Main.main(Main.java:1148)
at org.eclipse.core.launcher.Main.main(Main.java:30)
Caused by: java.lang.NullPointerException
at org.jboss.tools.vpe.editor.VpeController$ActiveEditorSwitcher.access$3(VpeController.java:1479)
at org.jboss.tools.vpe.editor.VpeController.notifyChangedInUiThread(VpeController.java:440)
at org.jboss.tools.vpe.editor.VpeController$2.runInUIThread(VpeController.java:428)
at org.eclipse.ui.progress.UIJob$1.run(UIJob.java:94)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:129)