code: func (flag *OutputFlag) Log(s string) (int, error) {
  	if len(s) > 0 && s[0] == '\r' {
  		flag.Write([]byte{'\r', 033, '[', 'K'})
  		s = s[1:]
  	}
  
  	return flag.WriteString(time.Now().Format("[02-01-06 15:04:05] ") + s)
  }
docs: // Log outputs the specified string, prefixed with the current time.
  // A newline is not automatically added. If the specified string
  // starts with a '\r', the current line is cleared first.