Bug 24250 Type Hierarchy doesn't show all inherited members on focus change
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
private void clearInput() {
		fInputElement= null;
		fHierarchyLifeCycle.freeHierarchy();
		
		updateHierarchyViewer();
		updateToolbarButtons();
	}
	/*
	 * @see IWorbenchPart#setFocus
	 */	
	public void setFocus() {
		fPagebook.setFocus();
	}
	/*
	 * @see IWorkbenchPart#dispose
	 */	
	public void dispose() {
		fHierarchyLifeCycle.freeHierarchy();
		fHierarchyLifeCycle.removeChangedListener(fTypeHierarchyLifeCycleListener);
		fPaneLabelProvider.dispose();
		
		if (fPropertyChangeListener != null) {
			JavaPlugin.getDefault().getPreferenceStore().removePropertyChangeListener(fPropertyChangeListener);
			fPropertyChangeListener= null;
		}
		
		getSite().getPage().removePartListener(fPartListener);
		if (fActionGroups != null)
			fActionGroups.dispose();