protected function compileGroupClasses($name, array $classes)
    {
        $path = "{$this->path}/{$name}";

        if (! $this->files->isDirectory($path)) {
            return ;
        }

        foreach ($classes as $class) {
            $file = "{$path}/{$class}.php";

            if ($this->files->exists($file)) {
                $this->collection['added'][] = $file;
            } else {
                $this->collection['missing'][] = $file;
            }
        }
    }