public static function registerExtension(string $fileExtension, $class)
    {
        if (
            in_array(
                'Aidantwoods\BetterOptions\FileLoader',
                class_implements($class),
                true
            )
        ) {
            self::$classMap[strtolower($fileExtension)] = $class;
        }
        else
        {
            throw new Exception(
                "Classes must implement the "
                ."Aidantwoods\BetterOptions\FileLoader interface in order to "
                ."be registered in the FileLoaderFactory. $class does not "
                ."implement this interface."
            );
        }
    }