protected function buildPostBody($js, $returnErrors = false)
    {
        return http_build_query(
            array_merge(
                self::$DEFAULT_OPTIONS,
                $this->additionalOptions,
                array(
                    'js_code' => $js,
                    'output_info' => ($returnErrors ? 'errors' : 'compiled_code')
                )
            ),
            null,
            '&'
        );
    }