Processor time when the alarm was acknowledged.

        :type: :class:`~datetime.datetime`

def acknowledge_time(self):
        """
        Processor time when the alarm was acknowledged.

        :type: :class:`~datetime.datetime`
        """
        if (self.is_acknowledged and
                self._proto.acknowledgeInfo.HasField('acknowledgeTime')):
            return parse_isostring(self._proto.acknowledgeInfo.acknowledgeTime)
        return None