Function start_incoming_packet_pipeline 

async fn start_incoming_packet_pipeline<WIn, WOut, D, T, TEvt, AckIn, AckOut, AppIn, AppInErr>(
    __arg0: (WOut, WIn),
    decoder: Arc<D>,
    ticket_proc: Arc<T>,
    ticket_events: TEvt,
    __arg4: (AckOut, AckIn),
    app_incoming: AppIn,
    counters: PeerProtocolCounterRegistry,
    concurrency: usize,
)
where
    WIn: Stream<Item = (PeerId, Box<[u8]>)> + Send + 'static,
    WOut: Sink<(PeerId, Box<[u8]>)> + Clone + Unpin + Send + 'static,
    WOut::Error: Error,
    D: PacketDecoder + Sync + Send + 'static,
    T: UnacknowledgedTicketProcessor + Send + 'static,
    TEvt: Sink<TicketEvent> + Clone + Unpin + Send + 'static,
    TEvt::Error: Error,
    AckIn: Sink<(OffchainPublicKey, Vec<Acknowledgement>)> + Send + Unpin + Clone + 'static,
    AckIn::Error: Error,
    AckOut: Sink<(OffchainPublicKey, Option<HalfKey>)> + Send + Unpin + Clone + 'static,
    AckOut::Error: Error,
    AppIn: Sink<(HoprPseudonym, ApplicationDataIn), Error = SinkTimeoutError<AppInErr>> + Send + 'static,
    AppInErr: Error,

Performs HOPR protocol decoding of incoming packets into Application protocol packets.

wire_incoming –> decoder –> ack_outgoing (final + forwarded) | –> wire_outgoing (forwarded) | –> ack_incoming (forwarded) | –> app_incoming (final)