How to save a model in Pytorch zip format - or get Pytorch to read a model in params format?

[juliangamble]

I'm on an M1 Mac - so I need to keep the env variable DJL_DEFAULT_ENGINE=PyTorch set to get any work done at all.

I'm trying to read a model I have trained which came out as
mymodel-0002.params
When I try and read it I get the error:

Exception in thread "main" ai.djl.engine.EngineException: PytorchStreamReader failed reading zip archive: failed finding central directory
	at ai.djl.pytorch.jni.PyTorchLibrary.moduleLoad(Native Method)
	at ai.djl.pytorch.jni.JniUtils.loadModule(JniUtils.java:1700)
	at ai.djl.pytorch.engine.PtModel.load(PtModel.java:92)
	at ai.djl.repository.zoo.BaseModelLoader.loadModel(BaseModelLoader.java:161)

(I've confirmed with the debugger it is looking in the correct directory and have set .optModelPath in the model loading Criteria). The problem is that the Pytorch library is looking for a zip file by default. (And it seems to have requirements around nested folders and versions etc). All I wanted to do was to load the mymodel.params file.

My question is: How to save a model in Pytorch zip format - or get Pytorch to read a model in params format?