docs: @Override
      public void unsubscribe(ClientIdentity clientIdentity) throws CanalServerException {
          CanalInstance canalInstance = canalInstances.get(clientIdentity.getDestination());
          canalInstance.getMetaManager().unsubscribe(clientIdentity); // 执行一下meta订阅
  
          logger.info("unsubscribe successfully, {}", clientIdentity);
      }