def METHOD_NAME(self, Create):
    Create.side_effect = fake_migration_create
    source = self.client.Dataset(1)
    target = self.client.Dataset(2)
    migration = source.migrate(target=target.id, follow=False)
    self.assertEqual(migration.source_id, source.id)
    self.assertEqual(migration.target_id, target.id)
    self.assertEqual(migration.commit_mode, 'append')