Parse and assign the topic for this trigger
        :param element: The XML Element object
        :type  element: etree._Element

def _parse_topic(self, element):
        """
        Parse and assign the topic for this trigger
        :param element: The XML Element object
        :type  element: etree._Element
        """
        self._log.debug('Setting Trigger topic: {topic}'.format(topic=element.text))
        super(Trigger, self)._parse_topic(element)