### Question:
DefaultOperationDiffValidatorFactory implements OperationDiffValidatorFactory { @Override public List<OperationDiffValidator> create() { List<OperationDiffValidator> validators = new ArrayList<>(); validators.add(new OperationParametersDiffValidator(parameterDiffValidatorFactory.create())); validators.add(new OperationRequestBodyDiffValidator(requestBodyDiffValidatorFactory.create())); validators.add(new OperationResponsesDiffValidator(responsesDiffValidatorFactory.create())); validators.add(new OperationDeleteNotAllowedDiffValidator()); validators.add(new OperationIdNotSameDiffValidator()); return Collections.unmodifiableList(validators); } DefaultOperationDiffValidatorFactory(
      ParameterDiffValidatorFactory parameterDiffValidatorFactory,
      RequestBodyDiffValidatorFactory requestBodyDiffValidatorFactory,
      ResponsesDiffValidatorFactory responsesDiffValidatorFactory); @Override List<OperationDiffValidator> create();  }### Answer:
@Test public void create() { List<OperationDiffValidator> validators = validatorFactory.create(); assertThat(validators).hasSize(5); }