'Deletes a group.'

@infinisdk_to_cinder_exceptions
def delete_group(self, context, group, volumes):

    if (not vol_utils.is_group_a_cg_snapshot_type(group)):
        raise NotImplementedError()
    try:
        infinidat_cg = self._get_infinidat_cg(group)
    except exception.InvalidGroup:
        pass
    else:
        infinidat_cg.safe_delete()
    for volume in volumes:
        self.delete_volume(volume)
    return (None, None)
