private function transformPostValues(array $postValues): string
    {
        $body = '';
        foreach ($postValues as $key => $value) {
            $body .= urlencode($key) . '=' . urlencode($value) . '&';
        }

        return $body;
    }
private function transformPostValues(array $postValues): string
    {
        $body = '';
        foreach ($postValues as $key => $value) {
            $body .= urlencode($key) . '=' . urlencode($value) . '&';
        }

        return $body;
    }
private function transformPostValues ( array $ postValues ) : string { $ body = '' ; foreach ( $ postValues as $ key => $ value ) { $ body .= urlencode ( $ key ) . '=' . urlencode ( $ value ) . '&' ; } return $ body ; }
transforms post values to post body

@param   array  $postValues
@return  string
transforms post values to post body