Bug 305739 [viewers] #expandToLevel(Object, level) retrieves all children when virtual
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
* 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;
		TreePath path;
		if (parentElementOrTreePath instanceof TreePath) {
			path = (TreePath) parentElementOrTreePath;
			parent = path.getLastSegment();
		} else {
			parent = parentElementOrTreePath;
			path = null;
		}
		
		
		if (widget instanceof Item) {
			Item ti = (Item) widget;
			if (!getExpanded(ti)) {
				boolean needDummy = isExpandable(ti, path, parent);
				boolean haveDummy = false;