public static Index withRelations(String name) {
    return new Index(name, true);
  }
@Test
  @UseDataProvider("nullOrEmpty")
  public void withRelations_index_constructor_fails_with_IAE_if_index_name_is_null_or_empty(String nullOrEmpty) {
    assertThatThrownBy(() -> Index.withRelations(nullOrEmpty))
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("Index name can't be null nor empty");
  }