@Test
public void toJsonReturnsExpected() {

    final RetrieveResourcesResponse underTest =
            RetrieveResourcesResponse.of(TestConstants.Policy.POLICY_ID, TestConstants.Policy.LABEL,
            TestConstants.Policy.RESOURCES, EMPTY_DITTO_HEADERS);
    final JsonObject actualJson = underTest.toJson(FieldType.regularOrSpecial());
    assertThat(actualJson).isEqualTo(KNOWN_JSON);
}