def to_xml(self, xml_declaration=True):
        """
        Return the contents of this verb as an XML string

        :param bool xml_declaration: Include the XML declaration. Defaults to True
        """
        xml = ET.tostring(self.xml()).decode('utf-8')
        return '<?xml version="1.0" encoding="UTF-8"?>{}'.format(xml) if xml_declaration else xml