@Test
public void toJsonWithoutRevision() {

    final PolicyCreated underTest = PolicyCreated.of(TestConstants.Policy.POLICY,
            TestConstants.Policy.REVISION_NUMBER, TestConstants.TIMESTAMP, TestConstants.EMPTY_DITTO_HEADERS);
    final Predicate<JsonField> isRevision =
            field -> field.getDefinition().map(definition -> definition == Event.JsonFields.REVISION).orElse(false);
    final JsonObject actualJson = underTest.toJson(isRevision.negate().and(FieldType.regularOrSpecial()));
    assertThat(actualJson).isEqualTo(KNOWN_JSON_WITHOUT_REVISION);
}