public function check($directories = null)
    {
        null == $directories && $directories = $this->directories;
        $return = array();
        $valid  = true;

        foreach ($directories as $path => $validationSpec) {
            $result                       = $this->checkDirectory($path, $validationSpec);
            $return['directories'][$path] = $result;
            $valid                        = $valid && $result['valid'];
        }
        $return['valid'] = $valid;

        return $return;
    }