Bug 89137 [JFace] - API Review - "temporary" API in AbstractTreeViewer
AbstractTreeViewer contains two methods documented as "temporary" internalRefresh(Widget, Object) internalAdd(Widget, Object, Object [])
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* Specifing <code>properties</code> as <code>null</code> forces a full
	 * update of the element.
	 * </p>
	 * <p>
	 * If the viewer has a sorter which is affected by a change to one of the
	 * properties, the element's position is updated to maintain the sort order.
	 * </p>
	 * <p>
	 * If the viewer has a filter which is affected by a change to one of the
	 * properties, the element may appear or disappear if the change affects
	 * whether or not the element is filtered out.
	 * </p>
	 * 
	 * @param element
	 *            the element
	 * @param properties
	 *            the properties that have changed, or <code>null</code> to
	 *            indicate unknown
	 */
	public void update(Object element, String[] properties) {
		Assert.isNotNull(element);
		Widget item = findItem(element);
		if (item == null)
			return;
		internalUpdate(item, element, properties);
	}
	/**
     * XXX: temporary API in support of Dirk's explorations
     * into grouping by working sets, which requires viewers
     * to support multiple equal elements.