TensorFlow 模型导出

我在 tf.saved_model.save(MLP, “saved/1”) 保存模型的时候 提示:ValueError: Expected an object of type Trackable, such as tf.Module or a subclass of the Trackable class, for export. Got <class ‘main.MLP’> with type <class ‘type’>.的错误 请大神帮我解答,谢谢