Bug 141192 [Viewers] Javadoc change about multiple equal elements in StructuredViewer and AbstractTreeViewer
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* </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[] items = findItems(element);
		for (int i = 0; i < items.length; i++) {
			internalUpdate(items[i], element, properties);
		}		
	}
	/**
     * Updates the given element's presentation when one or more of its
     * properties changes. Only the given element is updated.
     * <p>
     * EXPERIMENTAL.  Not to be used except by JDT.
     * This method was added to support JDT's explorations