code: def close(self):
          
          for pool in self.__pool.values():
              while not pool.empty():
                  conn = pool.get_nowait()
                  try:
                      self._close(conn)
                  except Exception:
                      pass
  
          # reset the pool size after closing all connections
          self.__poolSize.clear()
docs: Closes the connection to the database for this connection.
  
          :return     <bool> closed