code: func getFormatToken(format string) (token string, remain string, succ bool) {
  	if len(format) == 0 {
  		return "", "", true
  	}
  
  	// Just one character.
  	if len(format) == 1 {
  		if format[0] == '%' {
  			return "", "", false
  		}
  		return format, "", true
  	}
  
  	// More than one character.
  	if format[0] == '%' {
  		return format[:2], format[2:], true
  	}
  
  	return format[:1], format[1:], true
  }
docs: // getFormatToken takes one format control token from the string.
  // format "%d %H %m" will get token "%d" and the remain is " %H %m".