def _on_retire_connection_id_delivery(
        self, delivery: QuicDeliveryState, sequence_number: int
    ) -> None:
        """
        Callback when a RETIRE_CONNECTION_ID frame is acknowledged or lost.
        """
        if delivery != QuicDeliveryState.ACKED:
            self._retire_connection_ids.append(sequence_number)

        Callback when a RETIRE_CONNECTION_ID frame is acknowledged or lost.
        
src/aioquic/quic/connection.py