code: public ServiceFuture<List<Person>> listAsync(String personGroupId, ListPersonGroupPersonsOptionalParameter listOptionalParameter, final ServiceCallback<List<Person>> serviceCallback) {
          return ServiceFuture.fromResponse(listWithServiceResponseAsync(personGroupId, listOptionalParameter), serviceCallback);
      }
docs: List all persons in a person group, and retrieve person information (including personId, name, userData and persistedFaceIds of registered faces of the person).
  
  @param personGroupId Id referencing a particular person group.
  @param listOptionalParameter the object representing the optional parameters to be set before calling this API
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object