def update_face(large_face_list_id, persisted_face_id, user_data:nil, custom_headers:nil)
      response = update_face_async(large_face_list_id, persisted_face_id, user_data:user_data, custom_headers:custom_headers).value!
      nil
    end
def update_face(large_face_list_id, persisted_face_id, user_data:nil, custom_headers:nil)
      response = update_face_async(large_face_list_id, persisted_face_id, user_data:user_data, custom_headers:custom_headers).value!
      nil
    end
Update a persisted face's userData field.

 @param large_face_list_id [String] Id referencing a particular large face
 list.
 @param persisted_face_id Id referencing a particular persistedFaceId of an
 existing face.
 @param user_data [String] User-provided data attached to the face. The size
 limit is 1KB.
 @param custom_headers [Hash{String => String}] A hash of custom headers that
 will be added to the HTTP request.