code: public Observable<ServiceResponse<VerifyResult>> verifyFaceToPersonWithServiceResponseAsync(UUID faceId, String personGroupId, UUID personId) {
          if (this.client.azureRegion() == null) {
              throw new IllegalArgumentException("Parameter this.client.azureRegion() is required and cannot be null.");
          }
          if (faceId == null) {
              throw new IllegalArgumentException("Parameter faceId is required and cannot be null.");
          }
          if (personGroupId == null) {
              throw new IllegalArgumentException("Parameter personGroupId is required and cannot be null.");
          }
          if (personId == null) {
              throw new IllegalArgumentException("Parameter personId is required and cannot be null.");
          }
          VerifyFaceToPersonRequest bodyParameter = new VerifyFaceToPersonRequest();
          bodyParameter.withFaceId(faceId);
          bodyParameter.withPersonGroupId(personGroupId);
          bodyParameter.withPersonId(personId);
          String parameterizedHost = Joiner.on(", ").join("{AzureRegion}", this.client.azureRegion());
          return service.verifyFaceToPerson(this.client.acceptLanguage(), bodyParameter, parameterizedHost, this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<VerifyResult>>>() {
                  @Override
                  public Observable<ServiceResponse<VerifyResult>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<VerifyResult> clientResponse = verifyFaceToPersonDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Verify whether two faces belong to a same person. Compares a face Id with a Person Id.
  
  @param faceId FaceId the face, comes from Face - Detect
  @param personGroupId Using existing personGroupId and personId for fast loading a specified person. personGroupId is created in Person Groups.Create.
  @param personId Specify a certain person in a person group. personId is created in Persons.Create.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the VerifyResult object