@Test
public void toJsonReturnsExpected() {

    final RetrieveAttribute underTest =
            RetrieveAttribute.of(TestConstants.Thing.THING_ID, KNOWN_JSON_POINTER,
                    TestConstants.EMPTY_DITTO_HEADERS);
    final JsonObject actualJson = underTest.toJson(FieldType.regularOrSpecial());
    assertThat(actualJson).isEqualTo(KNOWN_JSON);
}