def test_resnet50_encoder_creation(self):
    backbone_options = config_pb2.ModelOptions.BackboneOptions(
        name='resnet50', output_stride=32)
    encoder = builder.create_encoder(
        backbone_options,
        tf.keras.layers.experimental.SyncBatchNormalization)
    self.assertIsInstance(encoder, axial_resnet_instances.ResNet50)