Bug 164509 Breaking API change: ColumnViewer#getItemAt(Point)
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* necessary.
	 * <p>
	 * This method should be called (by the content provider) when a single
	 * element has been removed from the model, in order to cause the viewer to
	 * accurately reflect the model. This method only affects the viewer, not
	 * the model. Note that there is another method for efficiently processing
	 * the simultaneous removal of multiple elements.
	 * </p>
	 * 
	 * @param elementsOrTreePaths
	 *            the element
	 */
	public void remove(Object elementsOrTreePaths) {
		remove(new Object[] { elementsOrTreePaths });
	}
	/**
	 * Removes all items from the given control.
	 * 
	 * @param control
	 *            the control
	 */
	protected abstract void removeAll(Control control);
	/**
	 * Removes a listener for expand and collapse events in this viewer. Has no
	 * affect if an identical listener is not registered.
	 * 
	 * @param listener
	 *            a tree viewer listener
	 */
	public void removeTreeListener(ITreeViewerListener listener) {