trducng

Looking at the classes in langchain/llms/openai.py and others, they don't inherit from pydantic.BaseModel so annotating disallowed_special with Collection[str] doesn't raise error. On the other hand, as OpenAIEmbeddings is a pydantic.BaseModel...

> Iterable is more generic than Collection and openai types as Collection, so probably don't want to do that. could we do Set[str] and Sequence[str]? probably covers anything people would...

@TobinPalmer Can you work on this PR. I have similar workaround and it would be great to have it resolved upstream.