code: public void updateFace(String personGroupId, UUID personId, UUID persistedFaceId, UpdateFaceOptionalParameter updateFaceOptionalParameter) {
          updateFaceWithServiceResponseAsync(personGroupId, personId, persistedFaceId, updateFaceOptionalParameter).toBlocking().single().body();
      }
docs: Update a person persisted face's userData field.
  
  @param personGroupId Id referencing a particular person group.
  @param personId Id referencing a particular person.
  @param persistedFaceId Id referencing a particular persistedFaceId of an existing face.
  @param updateFaceOptionalParameter the object representing the optional parameters to be set before calling this API
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws APIErrorException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent