Bug 305703 [Viewers][CommonNavigator] remembered contributions can leak when using filters
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
Item item = (Item) widget;
				TreePath p = getTreePathFromItem(item);
				if (p.equals(path)) {
					return widget;
				}
			}
		}
		return null;
	}
	/**
	 * Adds the given child elements to this viewer as children of the given
	 * parent element.
	 * <p>
	 * EXPERIMENTAL. Not to be used except by JDT. This method was added to
	 * support JDT's explorations into grouping by working sets. This method
	 * cannot be removed without breaking binary backwards compatibility, but
	 * should not be called by clients.
	 * </p>
	 *
	 * @param widget
	 *            the widget for the parent element
	 * @param parentElementOrTreePath
	 *            the parent element
	 * @param childElements
	 *            the child elements to add
	 * @since 3.1
	 */
	protected void internalAdd(Widget widget, Object parentElementOrTreePath,
			Object[] childElements) {
		Object parent;