code: def close(self):
          
  
          def validate_client(client):
              """
              Validate that the connection is for the current client
              :param client:
              :return:
              """
              host, port = client.addr
              parsed_url = urlparse(self._hostname)
              return host == parsed_url.hostname and port == parsed_url.port
  
          # read https://github.com/twisted/treq/issues/86
          # to understand the following...
          def _check_fds(_):
              fds = set(reactor.getReaders() + reactor.getReaders())
              if not [fd for fd in fds if isinstance(fd, Client) and validate_client(fd)]:
                  return
  
              return deferLater(reactor, 0, _check_fds, None)
  
          pool = self._async_http_client_params["pool"]
          return pool.closeCachedConnections().addBoth(_check_fds)
docs: close all http connections.
          returns a deferred that fires once they're all closed.