'Test deleting group snapshot
should throw NotImplementedError, is_group_a_cg_snapshot_type=False
otherwise returns model updates'

@mock.patch('cinder.volume.utils.is_group_a_cg_snapshot_type')
def test_delete_group_snapshot(self, is_group_a_cg_snapshot_type):

    is_group_a_cg_snapshot_type.side_effect = [False, True]
    self.set_https_response_mode(self.RESPONSE_MODE.Valid)
    self.snapshots[0].volume = self.volumes[0]
    self.snapshots[1].volume = self.volumes[1]
    self.snapshots[0].provider_id = fake.PROVIDER_ID
    self.snapshots[1].provider_id = fake.PROVIDER2_ID
    self.assertRaises(NotImplementedError, self.driver.delete_group_snapshot, self.ctx, self.group, self.snapshots)
    (result_model_update, result_snapshot_model_update) = self.driver.delete_group_snapshot(self.ctx, self.group, self.snapshots)
    self.assertEqual(fields.GroupSnapshotStatus.DELETED, result_model_update['status'])
    self.assertTrue(all(((snapshot['status'] == 'deleted') for snapshot in result_snapshot_model_update)))
