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
/**
	 * Return the item at the given path or <code>null</code>
	 * 
	 * @param path
	 *            the path
	 * @return {@link Widget} the item at that path 
	 */
	private Widget internalFindItem(TreePath path) {
		Widget[] widgets = findItems(path.getLastSegment());
		for (int i = 0; i < widgets.length; i++) {
			Widget widget = widgets[i];
			if (widget instanceof Item) {
				Item item = (Item) widget;
				TreePath p = getTreePathFromItem(item);
				if (p.equals(path)) {
					return widget;
				}
			}
		}
		return null;
	}
	/**
	 * Adds the given child elements to this viewer as children of the given
	 * parent element.
	 * <p>
	 * EXPERIMENTAL. Not to be used except by JDT. This method was added to
	 * support JDT's explorations into grouping by working sets, which requires
	 * viewers to support multiple equal elements. See bug 76482 for more
	 * details. This support will likely be removed in Eclipse 3.2 in favour of
	 * proper support for multiple equal elements.