public function getFilesWithExtension($path, $ext = 'php')
    {
        if (is_dir($path)) {
            return new RegexIterator(new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path, RecursiveDirectoryIterator::SKIP_DOTS), RecursiveIteratorIterator::SELF_FIRST, RecursiveIteratorIterator::CATCH_GET_CHILD // Ignore "Permission denied"
            ), '/^.+\.'.$ext.'$/i', RecursiveRegexIterator::GET_MATCH);
        } else {
            return [];
        }
    }