Function reply_decoded 

pub async fn reply_decoded<B>(
    request: &RnsRpcRequest,
    query: &impl NodeIntrospection,
    control: &impl RoutingControl,
    retention: &impl DestinationIdentityRetentionControl,
    blackholes: &B,
    blackhole_source: IdentityHash,
    transport_status: Option<RnsTransportStatus>,
) -> Result<Vec<u8>, RnsRpcReplyEncodeError>
where
    B: IdentityBlackholeSource + IdentityBlackholeControl,

Execute an already-decoded request and return the canonical MessagePack reply. Host transports use this after normalizing legacy pickle requests; the transport then re-encodes the reply in the request’s original dialect.