langchain/llms/openai.py/BaseOpenAI/_default_params
class BaseOpenAI:    def _default_params(self) -> Dict[str, Any]:
        """Get the default parameters for calling OpenAI API."""
        normal_params = {
            "temperature": self.temperature,
            "max_tokens": self.max_tokens,
            "top_p": self.top_p,
            "frequency_penalty": self.frequency_penalty,
            "presence_penalty": self.presence_penalty,
            "n": self.n,
            "request_timeout": self.request_timeout,
            "logit_bias": self.logit_bias,
        }

        # Azure gpt-35-turbo doesn't support best_of
        # don't specify best_of if it is 1
        if self.best_of > 1:
            normal_params["best_of"] = self.best_of

        return {**normal_params, **self.model_kwargs}