public function getFiles($root = null)
    {
        $root = $root ?: __DIR__ . '/../../../../';
        $root = realpath($root);

        if ($this->files == null) {
            $files = scandir($root);
            foreach ($files as $i => $file) {
                if (is_dir("$root/$file")) {
                    $files[$i] .= "/";
                }
            }
            $this->files = $files;
        }

        return $this->files;
    }