def update(upn_or_object_id, parameters, custom_headers:nil)
      response = update_async(upn_or_object_id, parameters, custom_headers:custom_headers).value!
      nil
    end
def update(upn_or_object_id, parameters, custom_headers:nil)
      response = update_async(upn_or_object_id, parameters, custom_headers:custom_headers).value!
      nil
    end
Updates a user.

 @param upn_or_object_id [String] The object ID or principal name of the user
 to update.
 @param parameters [UserUpdateParameters] Parameters to update an existing
 user.
 @param custom_headers [Hash{String => String}] A hash of custom headers that
 will be added to the HTTP request.