def schedule_servicegroup_host_downtime(self, servicegroup, start_time, end_time,
                                            fixed, trigger_id, duration, author, comment):
        """Schedule a host downtime for each host of services in a servicegroup
        Format of the line that triggers function call::

        SCHEDULE_SERVICEGROUP_HOST_DOWNTIME;<servicegroup_name>;<start_time>;<end_time>;<fixed>;
        <trigger_id>;<duration>;<author>;<comment>

        :param servicegroup: servicegroup to schedule downtime
        :type servicegroup: alignak.object.servicegroup.Servicegroup
        :param start_time: downtime start time
        :type start_time:
        :param end_time: downtime end time
        :type end_time:
        :param fixed: is downtime fixed
        :type fixed: bool
        :param trigger_id: downtime id that triggered this one
        :type trigger_id: str
        :param duration: downtime duration
        :type duration: int
        :param author: downtime author
        :type author: str
        :param comment: downtime comment
        :type comment: str
        :return: None
        """
        for host in [s.host for s in servicegroup.get_services()]:
            self.schedule_host_downtime(host, start_time, end_time, fixed,
                                        trigger_id, duration, author, comment)
Schedule a host downtime for each host of services in a servicegroup
        Format of the line that triggers function call::

        SCHEDULE_SERVICEGROUP_HOST_DOWNTIME;<servicegroup_name>;<start_time>;<end_time>;<fixed>;
        <trigger_id>;<duration>;<author>;<comment>

        :param servicegroup: servicegroup to schedule downtime
        :type servicegroup: alignak.object.servicegroup.Servicegroup
        :param start_time: downtime start time
        :type start_time:
        :param end_time: downtime end time
        :type end_time:
        :param fixed: is downtime fixed
        :type fixed: bool
        :param trigger_id: downtime id that triggered this one
        :type trigger_id: str
        :param duration: downtime duration
        :type duration: int
        :param author: downtime author
        :type author: str
        :param comment: downtime comment
        :type comment: str
        :return: None