@Test
public void detectsExtraObjectKeys() {

    Node actual = Node.objectNode().withMember("foo", Node.from("bar")).withMember("fizz", Node.from("buzz"));
    Node expected = Node.objectNode().withMember("foo", Node.from("bar"));
    assertThat(NodeDiff.diff(actual, expected),
               contains("[]: Extra key `fizz` encountered with content: \"buzz\""));
}