@Test
@SuppressWarnings("null")
public void testFactories() {

    assertThatThrownBy(() -> CubeId.root((String[]) null)).isInstanceOf(NullPointerException.class);
    assertThatThrownBy(() -> CubeId.root("hello", (String) null)).isInstanceOf(IllegalArgumentException.class);
    assertThatThrownBy(() -> CubeId.root((List<String>) null)).isInstanceOf(NullPointerException.class);
    assertThatThrownBy(() -> CubeId.root(Arrays.asList("hello", null))).isInstanceOf(IllegalArgumentException.class);
}