code: func getCacheHandler(w http.ResponseWriter, r *http.Request) {
  	target := r.URL.Path[len(cachePath):]
  	if target == "" {
  		w.WriteHeader(http.StatusBadRequest)
  		w.Write([]byte("can't get a key if there is no key."))
  		log.Print("empty request.")
  		return
  	}
  	entry, err := cache.Get(target)
  	if err != nil {
  		errMsg := (err).Error()
  		if strings.Contains(errMsg, "not found") {
  			log.Print(err)
  			w.WriteHeader(http.StatusNotFound)
  			return
  		}
  		log.Print(err)
  		w.WriteHeader(http.StatusInternalServerError)
  		return
  	}
  	w.Write(entry)
  }
docs: // handles get requests.