public NodeModel pathBegin(NodeModel commonAncestor) {
		return relativeNode(commonAncestor, beginPath, beginPath.length);
    }
@Test
	public void zeroLevelBegin(){
		final NodeModel parent = root();
		final NodeRelativePath nodeRelativePath = new NodeRelativePath(parent, parent);
		final NodeModel startingPoint = new NodeModel("startingPoint", map);
		assertThat(nodeRelativePath.pathBegin(startingPoint), equalTo(startingPoint));
	}