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
/**
	 * Creates an abstract tree viewer. The viewer has no input, no content
	 * provider, a default label provider, no sorter, no filters, and has
	 * auto-expand turned off.
	 */
	protected AbstractTreeViewer() {
		
	}
	/**
	 * Adds the given child elements to this viewer as children of the given
	 * parent element. If this viewer does not have a sorter, the elements are
	 * added at the end of the parent's list of children in the order given;
	 * otherwise, the elements are inserted at the appropriate positions.
	 * <p>
	 * This method should be called (by the content provider) when elements have
	 * been added to the model, in order to cause the viewer to accurately
	 * reflect the model. This method only affects the viewer, not the model.
	 * </p>
	 * 
	 * @param parentElementOrTreePath
	 *            the parent element
	 * @param childElements
	 *            the child elements to add
	 */
	public void add(Object parentElementOrTreePath, Object[] childElements) {
		Assert.isNotNull(parentElementOrTreePath);
		assertElementsNotNull(childElements);
		Widget[] widgets = internalFindItems(parentElementOrTreePath);
		
		if (widgets.length == 0) {