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
* @param control
	 *            the control
	 * @return the list of selected items
	 */
	protected abstract Item[] getSelection(Control control);
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.StructuredViewer#getSelectionFromWidget()
	 */
	protected List getSelectionFromWidget() {
		Widget[] items = getSelection(getControl());
		ArrayList list = new ArrayList(items.length);
		for (int i = 0; i < items.length; i++) {
			Widget item = items[i];
			Object e = item.getData();
			if (e != null) {
				list.add(e);
			}
		}
		return list;
	}
	/*
	 * Overridden in AbstractTreeViewer to fix bug 108102 (code copied from
	 * StructuredViewer to avoid introducing new API) (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.StructuredViewer#handleDoubleSelect(org.eclipse.swt.events.SelectionEvent)
	 */
	protected void handleDoubleSelect(SelectionEvent event) {