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: device_cache.rs
    path of file: ./repos/CYFS/src/component/cyfs-bdt/src/finder
    
    the code of the file until where you have to start completion: use std::{
    sync::{Mutex}, 
    time::Duration, 
    collections::{BTreeMap}
};
use lru_time_cache::LruCache;
use cyfs_base::*;
use super::outer
    
    pub fn add(&self, id: &DeviceId, device: &Device) {
        let real_device_id = device.desc().device_id();
        if *id != real_device_id {
            error!("add device but unmatch device_id! param_id={}, calc_id={}", id, real_device_id);
            // panic!("{}", msg);
            return;
        }

        {
            let mut cache = self.cache.lock().unwrap();
            cache.lru_caches.insert(id.clone(), device.clone());
        }

        if let Some(outer) = &self.outer {
            let outer = outer.clone_cache();
            let id = id.to_owned();
            let device = device.to_owned();
            
            async_std::task::spawn(async move {
                outer.add(&id, device).await;
            });
        }
    }