Bug 156883 [Viewers] enhancements to ILazyTreeContentProvider
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
Object parent;
		TreePath path;
		if (parentElementOrTreePath instanceof TreePath) {
			path = (TreePath) parentElementOrTreePath;
			parent = path.getLastSegment();
		} else {
			parent = parentElementOrTreePath;
			path = null;
		}
		if (parent != null) {
			if (equals(parent, getRoot())) {
				return super.getRawChildren(parent);
			}
			IContentProvider cp = getContentProvider();
			if (cp instanceof ITreePathContentProvider) {
				ITreePathContentProvider tpcp = (ITreePathContentProvider) cp;
				if (path == null) {
					
					Widget w = findItem(parent);
					if (w instanceof Item) {
						Item item = (Item) w;
						path = getTreePathFromItem(item);
					}
					if (path == null) {
						path = new TreePath(new Object[] { parent });
					}
				}
				Object[] result = tpcp.getChildren(path);
				if (result != null) {
					return result;