code: func (r *Response) fileExists(file string) bool {
  	if _, err := os.Stat(file); err == nil {
  		return true
  	}
  
  	r.Status = http.StatusNotFound
  	log.Warnf("cannot find %s file", file)
  	return false
  }
docs: // Checking if file exist.
  // todo: consider moving this to utils.go