testGetLastChild() {
    setUpDomTree();

    assertNull('Has no none ws children', editorNode.getLastChild(childNode2));
    assertEquals(
        'Should skip last child, as it is ws', gChildTextNode1,
        editorNode.getLastChild(childNode1));
    assertEquals(
        'Should just return last child', gChildTextNode3b,
        editorNode.getLastChild(childNode3));
    assertEquals(
        'Should return last child', childNode3,
        editorNode.getLastChild(parentNode));

    assertNull(
        'Last child of a text node should return null',
        editorNode.getLastChild(gChildTextNode1));
    assertNull(
        'Last child of null should return null',
        editorNode.getLastChild(gChildTextNode1));

    tearDownDomTree();
  }
Create a DOM tree and test that getLastChild properly ignores
ignorable nodes