code: def reset_rammbock(self):
          
          for client in self._clients:
              client.close()
          for server in self._servers:
              server.close()
          self._init_caches()
docs: Closes all connections, deletes all servers, clients, and protocols.
  
          You should call this method before exiting your test run. This will
          close all the connections and the ports will therefore be available for
          reuse faster.