code: def info(self, user_id):
          
          resp = self._rtm_client.get('v1/user.info?user_id={}'.format(user_id))
          if resp.is_fail():
              raise RTMServiceError('Failed to get user information', resp)
  
          return resp.data['result']
docs: Gets user information by user id
  
          Args:
              user_id(int): the id of user
  
          Returns:
              User
  
          Throws:
              RTMServiceError when request failed