def METHOD_NAME(model_dir, model):
    model.symbol.METHOD_NAME(os.path.join(model_dir, "model-symbol.json"))
    model.save_params(os.path.join(model_dir, "model-0000.params"))
    signature = [
        {"name": data_desc.name, "shape": [dim for dim in data_desc.shape]}
        for data_desc in model.data_shapes
    ]
    with open(os.path.join(model_dir, "model-shapes.json"), "w") as f:
        json.dump(signature, f)