def register(user_name, register_payload, custom_headers:nil)
      response = register_async(user_name, register_payload, custom_headers:custom_headers).value!
      nil
    end
def register(user_name, register_payload, custom_headers:nil)
      response = register_async(user_name, register_payload, custom_headers:custom_headers).value!
      nil
    end
Register a user to a managed lab

 @param user_name [String] The name of the user.
 @param register_payload [RegisterPayload] Represents payload for Register
 action.
 @param custom_headers [Hash{String => String}] A hash of custom headers that
 will be added to the HTTP request.