code: def set_topic(self, topic):
          
          if not topic:
              topic = ''
          result = self._connection.put("room/%s" % self.id, {"room": {"topic": topic}})
          if result["success"]:
              self._load()
  
          return result["success"]
docs: Set the room topic.
  
          Args:
              topic (str): Topic
  
          Returns:
              bool. Success