code: func (c *Cache) getString(id string) string {
  	id = cleanID(id)
  
  	c.nlocker.Lock(id)
  	defer c.nlocker.Unlock(id)
  
  	f, err := c.Fs.Open(id)
  
  	if err != nil {
  		return ""
  	}
  	defer f.Close()
  
  	b, _ := ioutil.ReadAll(f)
  	return string(b)
  
  }
docs: // For testing