'Create a group replica.
This can be a group snapshot or a cloned volume group.
:param source_group: the group object
:param snap_name: the name of the snapshot'

def _create_group_replica(self, source_group, snap_name):

    (array, __) = self.utils.get_volume_group_utils(source_group, self.interval, self.retries)
    vol_grp_name = None
    volume_group = self._find_volume_group(array, source_group)
    if volume_group:
        if ('name' in volume_group):
            vol_grp_name = volume_group['name']
    if (vol_grp_name is None):
        exception_message = (_('Cannot    find    generic    volume    group    %(group_id)s.') % {'group_id': source_group.id})
        raise exception.VolumeBackendAPIException(data=exception_message)
    interval_retries_dict = self.utils.get_intervals_retries_dict(self.interval, self.retries)
    self.provision.create_group_replica(array, vol_grp_name, snap_name, interval_retries_dict)
