code: func (d *DBConfig) URL() (string, error) {
  	if d.DBConnectFile != "" {
  		url, err := ioutil.ReadFile(d.DBConnectFile)
  		return strings.TrimSpace(string(url)), err
  	}
  	return d.DBConnect, nil
  }
docs: // URL returns the DBConnect URL represented by this DBConfig object, either
  // loading it from disk or returning a default value. Leading and trailing
  // whitespace is stripped.