testGetContainer() {
    setUpGetNodeFunctions();
    assertEquals(
        'Should return self', childNode1, style.getContainer(childNode1));
    assertEquals(
        'Should return parent', childNode1, style.getContainer(gChildWsNode1));
    assertNull('Document has no ancestors', style.getContainer(document));
    tearDownGetNodeFunctions();
  }
Test that getContainer properly returns the node itself if it is a
container, an ancestor node if it is a container, and null otherwise