protected static function parseFormat($format)
    {
        static::loadFormats();

        // If the format equals a constant's value, just return it.
        if (in_array($format, static::$formats, true)) {
            return $format;
        }

        // Otherwise we'll assume the format is the constant's name.
        return Arr::get(static::$formats, strtoupper($format));
    }