`addAssistantMessage` method is missing

[ruofeilyu]

[TomerAberbach]

You can call addMessage with a ChatCompletionAssistantMessageParam

@kwhinnery-openai is it intentional that content on an assistant message is optional? That's the reason we don't generate addAssistantMessage here (we only generate such methods when there's a single required field)

[ruofeilyu]

I also found the ChatCompletionAssistantMessageParam, yeah it works, but still feel it's weird that addAssistantMessage does not exist. Thanks

[ruofeilyu]

feel not very elegant.