code: public Observable<ServiceResponse<List<IdentifyResult>>> identifyWithServiceResponseAsync(String personGroupId, List<UUID> faceIds, IdentifyOptionalParameter identifyOptionalParameter) {
          if (this.client.azureRegion() == null) {
              throw new IllegalArgumentException("Parameter this.client.azureRegion() is required and cannot be null.");
          }
          if (personGroupId == null) {
              throw new IllegalArgumentException("Parameter personGroupId is required and cannot be null.");
          }
          if (faceIds == null) {
              throw new IllegalArgumentException("Parameter faceIds is required and cannot be null.");
          }
          Validator.validate(faceIds);
          final Integer maxNumOfCandidatesReturned = identifyOptionalParameter != null ? identifyOptionalParameter.maxNumOfCandidatesReturned() : null;
          final Double confidenceThreshold = identifyOptionalParameter != null ? identifyOptionalParameter.confidenceThreshold() : null;
  
          return identifyWithServiceResponseAsync(personGroupId, faceIds, maxNumOfCandidatesReturned, confidenceThreshold);
      }
docs: Identify unknown faces from a person group.
  
  @param personGroupId PersonGroupId of the target person group, created by PersonGroups.Create
  @param faceIds Array of query faces faceIds, created by the Face - Detect. Each of the faces are identified independently. The valid number of faceIds is between [1, 10].
  @param identifyOptionalParameter the object representing the optional parameters to be set before calling this API
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;IdentifyResult&gt; object