Bug 171649 [Viewers] AbstractTreeViewerisExpandable(elementOrTreePath) is not called when using a ITreePathContentProvider
Build ID: 3.3M3 More information: see AbstractTreeViewer.java, line 1974, the content provider hasChildren() should not be called directly
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
*            <code>true</code> to update labels for existing elements,
	 *            <code>false</code> to only update labels as needed, assuming
	 *            that labels for existing elements are unchanged.
	 * @since 3.1
	 */
	protected void internalRefresh(Widget widget, Object element,
			boolean doStruct, boolean updateLabels) {
		if (widget instanceof Item) {
			if (doStruct) {
				updatePlus((Item) widget, element);
			}
			if (updateLabels || !equals(element, widget.getData())) {
				doUpdateItem(widget, element, true);
			} else {
				associate(element, (Item) widget);
			}
		}
		if (doStruct) {
			internalRefreshStruct(widget, element, updateLabels);
		} else {
			Item[] children = getChildren(widget);
			if (children != null) {
				for (int i = 0; i < children.length; i++) {
					Widget item = children[i];
					Object data = item.getData();
					if (data != null) {
						internalRefresh(item, data, doStruct, updateLabels);
					}
				}
			}