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
* Adds support for dragging items out of this viewer via a user
	 * drag-and-drop operation.
	 * 
	 * @param operations
	 *            a bitwise OR of the supported drag and drop operation types (
	 *            <code>DROP_COPY</code>,<code>DROP_LINK</code>, and
	 *            <code>DROP_MOVE</code>)
	 * @param transferTypes
	 *            the transfer types that are supported by the drag operation
	 * @param listener
	 *            the callback that will be invoked to set the drag data and to
	 *            cleanup after the drag and drop operation finishes
	 * @see org.eclipse.swt.dnd.DND
	 */
	public void addDragSupport(int operations, Transfer[] transferTypes, DragSourceListener listener) {
		Control myControl = getControl();
		final DragSource dragSource = new DragSource(myControl, operations);
		dragSource.setTransfer(transferTypes);
		dragSource.addDragListener(listener);
	}
	/**
	 * Adds support for dropping items into this viewer via a user drag-and-drop
	 * operation.
	 * 
	 * @param operations
	 *            a bitwise OR of the supported drag and drop operation types (
	 *            <code>DROP_COPY</code>,<code>DROP_LINK</code>, and
	 *            <code>DROP_MOVE</code>)
	 * @param transferTypes
	 *            the transfer types that are supported by the drop operation