public static function filter($name, $handler)
    {
        if (! $handler instanceof \Closure and ! in_array(Filter::class, class_implements($handler), false)) {
            throw new \InvalidArgumentException("Failed adding Filter. Provided handler for [{$name}] is not valid. Must either provide a \\Closure or classpath that impelments \\Docit\\Docit\\Contracts\\Filter");
        }

        static::$filters[ $name ] = $handler;
    }