'Verify that an element has no aria-describedby attribute if there are no descriptions.
Arguments:
describedby_xpaths (list): list of xpaths to check aria-describedby attribute'

def assert_describedby_attribute(self, describedby_xpaths):

    self.context['describedby_html'] = ''
    xml = self.render_to_xml(self.context)
    for describedby_xpath in describedby_xpaths:
        describedbys = xml.xpath(describedby_xpath)
        self.assertFalse(describedbys)
