Bug 153943 [Viewers] Rename new API, e.g. RowPart -> ViewerRow
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
*/
	protected void internalRefreshStruct(Widget widget, Object element,
			boolean updateLabels) {
		if (getContentProvider() instanceof ILazyTreeContentProvider) {
			
			virtualRefreshChildCounts(widget, element);
			
			if (updateLabels) {
				if (widget instanceof Tree) {
					((Tree) widget).clearAll(true);
				} else if (widget instanceof TreeItem) {
					((TreeItem) widget).clearAll(true);
				}
			}
			return;
		}
		super.internalRefreshStruct(widget, element, updateLabels);
	}
	/**
	 * Traverses the visible (expanded) part of the tree and updates child
	 * counts.
	 * 
	 * @param widget
	 * @param element
	 * @param updateLabels
	 */
	private void virtualRefreshChildCounts(Widget widget, Object element) {
		ILazyTreeContentProvider lazyTreeContentProvider = (ILazyTreeContentProvider) getContentProvider();
		if (widget instanceof Tree || ((TreeItem) widget).getExpanded()) {