Bug 28575 Hierarchy view updates items twice [type hierarchy]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
if (!(element instanceof IJavaElement))
			return;
				
		IJavaElement openable= (IJavaElement) ((IJavaElement) element).getOpenable();
		IResource resource= openable.getResource();	
		if (!(resource instanceof IFile))
			return; 
		
		MenuManager submenu= new MenuManager(TypeHierarchyMessages.getString("TypeHierarchyViewPart.menu.open")); 
		submenu.add(new OpenWithMenu(getSite().getPage(), (IFile) resource));
		
		menu.appendToGroup(IContextMenuConstants.GROUP_OPEN, submenu);
	}
	/**
	 * Toggles between the empty viewer page and the hierarchy
	 */
	private void setViewerVisibility(boolean showHierarchy) {
		if (showHierarchy) {
			fViewerbook.showPage(getCurrentViewer().getControl());
		} else {
			fViewerbook.showPage(fEmptyTypesViewer);
		}
	}
	
	/**
	 * Sets the member filter. <code>null</code> disables member filtering.
	 */	
	private void setMemberFilter(IMember[] memberFilter) {
		Assert.isNotNull(fAllViewers);
		for (int i= 0; i < fAllViewers.length; i++) {