protected function _normalizeData($args, $path = '')
    {
        $data = [];
        foreach ($args as $key => $value) {
            if ($path) {
                // Fold string keys with [].
                // Numeric keys result in a=b&a=c. While this isn't
                // standard behavior in PHP, it is common in other platforms.
                if (!is_numeric($key)) {
                    $key = "{$path}[{$key}]";
                } else {
                    $key = $path;
                }
            }
            if (is_array($value)) {
                uksort($value, 'strcmp');
                $data = array_merge($data, $this->_normalizeData($value, $key));
            } else {
                $data[] = [$key, $value];
            }
        }

        return $data;
    }