'Deletes a group_snapshot.'

@infinisdk_to_cinder_exceptions
def delete_group_snapshot(self, context, group_snapshot, snapshots):

    if (not vol_utils.is_group_a_cg_snapshot_type(group_snapshot)):
        raise NotImplementedError()
    cgsnap_name = self._make_group_snapshot_name(group_snapshot)
    infinidat_cgsnap = self._system.cons_groups.safe_get(name=cgsnap_name)
    if (infinidat_cgsnap is not None):
        if (not infinidat_cgsnap.is_snapgroup()):
            msg = (_('Group    "%s"    is    not    a    snapshot    group') % cgsnap_name)
            LOG.error(msg)
            raise exception.InvalidGroupSnapshot(message=msg)
        infinidat_cgsnap.safe_delete()
    for snapshot in snapshots:
        self.delete_snapshot(snapshot)
    return (None, None)
