public abstract BuiltIndex<T> build();
@Test
  @UseDataProvider("indexAndTypeMappings")
  public void fail_when_nested_with_no_field(NewIndex<?> newIndex, TypeMapping typeMapping) {
    NestedFieldBuilder<TypeMapping> nestedFieldBuilder = typeMapping.nestedFieldBuilder("measures");

    assertThatThrownBy(() -> nestedFieldBuilder.build())
      .isInstanceOf(IllegalArgumentException.class)
      .hasMessage("At least one sub-field must be declared in nested property 'measures'");
  }