You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/spotify-connect-scrobbler/core/src/mercury
    
    the code of the file until where you have to start completion: use byteorder::{BigEndian, ByteOrder};
use futures::sync::{oneshot, mpsc};
use futures::{Async, Poll, BoxFuture, Future};
use protobuf;
use protocol;
use std::collections::HashMap;
use std::mem;
use tokio_core::io::EasyBuf;

use util::SeqGenerator;

mod types;
pub use self::types::*;

mod sender;
pub use self::sender::MercurySender;

component! {
    MercuryManager : MercuryManagerInner {
    
    
    fn complete_request(&self, cmd: u8, mut pending: MercuryPending) {
        let header_data = pending.parts.remove(0);
        let header: protocol::mercury::Header = protobuf::parse_from_bytes(&header_data).unwrap();

        let response = MercuryResponse {
            uri: header.get_uri().to_owned(),
            status_code: header.get_status_code(),
            payload: pending.parts,
        };

        if response.status_code >= 400 {
            warn!("error {} for uri {}", response.status_code, &response.uri);
            if let Some(cb) = pending.callback {
                cb.complete(Err(MercuryError));
            }
        } else {
            if cmd == 0xb5 {
                self.lock(|inner| {
                    let mut found = false;
                    inner.subscriptions.retain(|&(ref prefix, ref sub)| {
                        if response.uri.starts_with(prefix) {
                            found = true;

                            // if send fails, remove from list of subs
                            // TODO: send unsub message
                            sub.send(response.clone()).is_ok()
                        } else {
                            // URI doesn't match
                            true
                        }
                    });

                    if !found {
                        debug!("unknown subscription uri={}", response.uri);
                    }
                })
            } else if let Some(cb) = pending.callback {
                cb.complete(Ok(response));
            }
        }
    }