'Deletes a group snapshot.
For more information, please refer to the official API reference:
https://developer.openstack.org/api-ref/block-storage/v3/#delete-group-snapshot'

def delete_group_snapshot(self, group_snapshot_id):

    (resp, body) = self.delete(('group_snapshots/%s' % group_snapshot_id))
    self.expected_success(202, resp.status)
    return rest_client.ResponseBody(resp, body)
