Bug 28563 NPE on shutdown when JUnit view wasn't realized
org.eclipse.jdt.junit/src/org/eclipse/jdt/internal/junit/ui/TestRunnerViewPart.java
public StopAction() {
			setText(JUnitMessages.getString("TestRunnerViewPart.stopaction.text"));
			setToolTipText(JUnitMessages.getString("TestRunnerViewPart.stopaction.tooltip"));
			setDisabledImageDescriptor(JUnitPlugin.getImageDescriptor("dlcl16/stop.gif")); 
			setHoverImageDescriptor(JUnitPlugin.getImageDescriptor("clcl16/stop.gif")); 
			setImageDescriptor(JUnitPlugin.getImageDescriptor("elcl16/stop.gif")); 
		}
		public void run() {
			stopTest();
		}
	}
	private class RerunAction extends Action{
		public RerunAction() {
			setText(JUnitMessages.getString("TestRunnerViewPart.rerunaction.label")); 
			setToolTipText(JUnitMessages.getString("TestRunnerViewPart.rerunaction.tooltip")); 
			setDisabledImageDescriptor(JUnitPlugin.getImageDescriptor("dlcl16/relaunch.gif")); 
			setHoverImageDescriptor(JUnitPlugin.getImageDescriptor("clcl16/relaunch.gif")); 
			setImageDescriptor(JUnitPlugin.getImageDescriptor("elcl16/relaunch.gif")); 
		}
		
		public void run(){
			rerunTestRun();
		}
	}
	
	/**
	 * Listen for for modifications to Java elements
	 */
	private class DirtyListener implements IElementChangedListener {