Include ChatGPT Turbo model in the Chain (Summarization)
im assuming you mean update the typing? Currently, with: 
`llm = OpenAI(model_name= "gpt-3.5-turbo" ,temperature=0)`

It loads OpenAIChat and feeding OpenAIChat into 
```summary_chain = load_summarize_chain(llm, chain_type="map_reduce", map_prompt=PROMPT, combine_prompt=PROMPT, verbose=True)```

Will lead to the following error:
```ValueError: OpenAIChat currently only supports single prompt, got [Wha...```


I don't know if it is the same issue nsankar referring to. But I think it would be a great improvement as text-davinci-003 is super expensive compared to gpt-3.5-turbo. In particular for map_reduce summarization as it makes a lot of API calls...

If it's not the same issue, I can open a new issue  The issue is the same as I posted here: https://github.com/hwchase17/langchain/issues/1368#issuecomment-1461853402

Chat models don't work for summarization in langchain, but there is no good reason for this. It is very easy to make chat models act like normal models, would suggest just doing that. If you are desperate to get this working, you can cherrypick the commit I made here: https://github.com/hwchase17/langchain/pull/1826

Then you can use turbo and gpt4 for chains etc.
Please include  ChatGPT Turbo's ChatOpenAI  object to be passed as an LLM completion in the Summarizer chain.
_(from langchain.chat_models.openai import ChatOpenAI)_

for the following usage
`summary_chain = load_summarize_chain(llm, chain_type="map_reduce")
summarize_document_chain = AnalyzeDocumentChain(combine_docs_chain=summary_chain)`