How to use the branca.element.IFrame function in branca

def test_rendering_utf8_iframe():
    iframe = elem.IFrame(html=u'<p>Cerrahpaşa Tıp Fakültesi</p>')

    options = Options()
    options.add_argument('-headless')
    driver = Firefox(options=options)

    driver.get('data:text/html,' + iframe.render())
    driver.switch_to.frame(0)
    assert u'Cerrahpaşa Tıp Fakültesi' in driver.page_source

def render(self, **kwargs):
        """Renders the HTML representation of the element."""
        html = super(IFrame, self).render(**kwargs)
        html = "data:text/html;charset=utf-8;base64," + base64.b64encode(html.encode('utf8')).decode('utf8')  # noqa

        if self.height is None:
            iframe = (
                '<div style="width:{width};">'
                '<div style="position:relative;width:100%;height:0;padding-bottom:{ratio};">'  # noqa
                ''
                '</div></div>'
            ).format(html=html, width=self.width, ratio=self.ratio)
        else:
            iframe = (
                ''
            ).format(html=html, width=self.width, height=self.height)