Function start_outgoing_ack_pipeline 

async fn start_outgoing_ack_pipeline<AckOut, E, WOut>(
    ack_outgoing: AckOut,
    encoder: Arc<E>,
    cfg: AcknowledgementPipelineConfig,
    packet_key: OffchainKeypair,
    wire_outgoing: WOut,
)
where
    AckOut: Stream<Item = (OffchainPublicKey, Option<HalfKey>)> + Send + 'static,
    E: PacketEncoder + Sync + Send + 'static,
    WOut: Sink<(PeerId, Box<[u8]>)> + Clone + Unpin + Send + 'static,
    WOut::Error: Error,