如何通过LangChains检索源文件——只有当答案来自习俗知识基础时,才会有相关性。
原文：How to retrieve source documents via LangChain s get_relevant_documents method only if the answer is from the custom knowledge base

I am making a chatbot which accesses an external knowledge base docs. I want to get the relevant documents the bot accessed for its answer, but this shouldn t be the case when the user input is ...