Model saving API in swift for tensorflow

Hi, I'm using swift for tensorflow in my reinforcement project, which is really awesome because the language is strongly typed, it helps to construct a large scale project easily and also we could develop faster by the LSP support.
However, I couldn't find how to save a trained model throughout the S4TF native API? I saw a topic saying it's not officially provided now (I lost the link though...).
Is it impossible ? or is there any alternative?