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