protected function getFileTypeClass(/*# string */ $filename)
    {
        $parts  = explode('.', strtolower(basename($filename)));
        $count  = count($parts);
        $suffix = $count > 1 ? $parts[$count - 1] : 'php';
        $type   = $count > 2 ? $parts[$count - 2][0] : '_';

        // valid types
        $types  = ['s' => 'services', 'p' => 'parameters', 'm' => 'mappings'];

        return [
            isset($types[$type]) ? $types[$type] : false,
            $this->getLoaderClass($suffix, $filename)
        ];
    }