code: def get(self, agentml, user=None, key=None):
          
          user = agentml.get_user(key) if key else user
          if not user:
              return
  
          return user.id
docs: Evaluate and return the current active topic
          :param user: The active user object
          :type  user: agentml.User or None
  
          :param agentml: The active AgentML instance
          :type  agentml: AgentML
  
          :param key: The user id (defaults to the current user if None)
          :type  key: str
  
          :return: Active topic of the user
          :rtype : str or None