public final function setUrl($url)
    {
        if (is_string($url)) {

            $this->_url = new ehough_curly_Url($url);

            return;
        }

        if (! $url instanceof ehough_curly_Url) {

            throw new ehough_shortstop_api_exception_InvalidArgumentException(
                'setUrl() only takes a string or a ehough_curly_Url instance'
            );
        }

        $this->_url = $url;
    }