code: public void endConnection(SuroConnection connection) {
          if (connection != null && shouldChangeConnection(connection)) {
              connection.initStat();
              connectionPool.put(connection.getServer(), connection);
              connection = chooseFromPool();
          }
  
          if (connection != null) {
              connectionQueue.offer(connection);
          }
      }
docs: When the client finishes communication with the client, this method
  should be called to release the connection and return it to the pool.
  @param connection