langchain/llms/base.py/update_cache
def update_cache(
    existing_prompts: Dict[int, List],
    llm_string: str,
    missing_prompt_idxs: List[int],
    new_results: LLMResult,
    prompts: List[str],
) -> Optional[dict]:
    """Update the cache and get the LLM output."""
    for i, result in enumerate(new_results.generations):
        existing_prompts[missing_prompt_idxs[i]] = result
        prompt = prompts[missing_prompt_idxs[i]]
        if langchain.llm_cache is not None:
            langchain.llm_cache.update(prompt, llm_string, result)
    llm_output = new_results.llm_output
    return llm_output