@Test(expected = AssertionError.class)
 public void testAssertThat_node_has_changed_state_fails_when_node_has_different_state() {
   final Node node = new DefaultNode(String.class);
   node.setState(Node.State.UNTOUCHED);
   assertThat(node).node().hasState(Node.State.CHANGED);
 }
 @Test
 public void testAssertThat_node_has_changed_state_succeeds_when_node_has_changed() {
   final Node node = new DefaultNode(String.class);
   node.setState(Node.State.CHANGED);
   assertThat(node).node().hasState(Node.State.CHANGED);
 }