code: func Parse(s string) (os.Signal, error) {
  	sig, ok := SignalLookup[strings.ToUpper(s)]
  	if !ok {
  		return nil, fmt.Errorf("invalid signal %q - valid signals are %q",
  			s, ValidSignals)
  	}
  	return sig, nil
  }
docs: // Parse parses the given string as a signal. If the signal is not found,
  // an error is returned.