, since they're in
    // different trees?  Since the DOMs are the same, it's enough to check
    // that the index in the parent is the same all the way up the tree.
    // But we can first cheat by just checking they're actually equal.
    assert_true(actualRange.startContainer.isEqualNode(expectedRange.startContainer),
      "Unexpected startContainer after cloneContents(), expected " +
      expectedRange.startContainer.nodeName.toLowerCase() + " but got " +
      actualRange.startContainer.nodeName.toL