code: public void onInfoChanged(AVIMClient client, AVIMConversation conversation, JSONObject attr,
                              String operator) {
      LOGGER.d("Notification --- " + operator + " by member: " + operator + ", changedTo: " + attr.toJSONString());
    }
docs: 对话自身属性变更通知
  
  @param client
  @param conversation
  @param attr
  @param operator