code: def _serve_forever_wrapper(self, _srv, poll_interval=0.1):
          
          self.logger.info('Opening tunnel: {0} <> {1}'.format(
              address_to_str(_srv.local_address),
              address_to_str(_srv.remote_address))
          )
          _srv.serve_forever(poll_interval)  # blocks until finished
  
          self.logger.info('Tunnel: {0} <> {1} released'.format(
              address_to_str(_srv.local_address),
              address_to_str(_srv.remote_address))
          )
docs: Wrapper for the server created for a SSH forward