code: def set_min_requests_per_connection(self, host_distance, min_requests):
          
          if self.protocol_version >= 3:
              raise UnsupportedOperation(
                  "Cluster.set_min_requests_per_connection() only has an effect "
                  "when using protocol_version 1 or 2.")
          if min_requests < 0 or min_requests > 126 or \
             min_requests >= self._max_requests_per_connection[host_distance]:
              raise ValueError("min_requests must be 0-126 and less than the max_requests for this host_distance (%d)" %
                               (self._min_requests_per_connection[host_distance],))
          self._min_requests_per_connection[host_distance] = min_requests
docs: Sets a threshold for concurrent requests per connection, below which
          connections will be considered for disposal (down to core connections;
          see :meth:`~Cluster.set_core_connections_per_host`).
  
          Pertains to connection pool management in protocol versions {1,2}.