Bug 119076 [Markers] ArrayStoreException when multiselection in Problems view includes category
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/ProblemView.java
void addDropDownContributions(IMenuManager menu) {
		menu.add(getFlatAction());
		menu.add(getHierarchalAction());
		super.addDropDownContributions(menu);
	}
	/**
	 * Return the action for setting hierarchal mode.
	 * 
	 * @return IAction
	 */
	private IAction getHierarchalAction() {
		IAction hierarchalAction = new Action() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.jface.action.Action#getStyle()
			 */
			public int getStyle() {
				return AS_RADIO_BUTTON;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.jface.action.Action#getText()
			 */
			public String getText() {
				return MarkerMessages.ProblemView_hierarchyMenu;
			}
			/*
			 * (non-Javadoc)