Metaclass conflict error with LangChain 0.3.x

[minki-j]

  File "notdiamond/llms/client.py", line 539, in _ndllm_factory
    class _NDInvokerClient(_NDRouterClient, LLM):
TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases

I ran into this error with langchain version of 0.3.x. I've tested with lower versions and confirmed that it worked fine.

Since I'm not using "create" but only "model_select", Not Diamond should work fine but this error prevents me from running the code.

[minki-j]

In this commit, I added the init_NotDiamond_client function with a router_only parameter to get around this issue.

Obviously this is not a good idea; since the NotDiamond class is hidden within the function, it is not backward compatible.

That said, I believe it would be beneficial to have a way to define the client class with parameters. From what I’ve seen, import_target is not currently used in the codebase.

I’d love to hear your thoughts on this design choice and the reasoning behind the current implementation. Thanks!