public static function loadExtensionsFiles($files, array $config = []) : array
    {
        $callbacks = [];
        $files     = !is_array($files) ? static::findExtensionsFiles($files) : $files;
        foreach ($files as $file) {
            $item = require  $file;
            if ($item instanceof \Closure) {
                $callbacks[] = $item;
            }
            if (is_array($item)) {
                $config = array_replace_recursive($config, $item);
            }
        }
        foreach ($callbacks as $callback) {
            $config = $callback($config);
        }
        return $config;
    }