@Test
public void toJsonReturnsExpected() {

    final ModifyAcl underTest =
            ModifyAcl.of(TestConstants.Thing.THING_ID, TestConstants.Thing.ACL,
                    TestConstants.EMPTY_DITTO_HEADERS);
    final JsonObject actualJson = underTest.toJson(JsonSchemaVersion.V_1, FieldType.regularOrSpecial());
    assertThat(actualJson).isEqualTo(KNOWN_JSON);
}