@Test
public void getParent() {

    ObjectValue n = PropertyValue.createObject("");
    assertThat(n.getParent()).isNull();
    PropertyValue val = n.addObject("b");
    assertThat(n.getValue("b")).isNotNull();
    assertThat(val).isEqualTo(n.getPropertyValue("b"));
    assertThat(n.getPropertyValue("b").getParent()).isNotNull();
}