langchain/chains/conversational_retrieval/base.py/ChatVectorDBChain/_get_docs
class ChatVectorDBChain:    def _get_docs(self, question: str, inputs: Dict[str, Any]) -> List[Document]:
        vectordbkwargs = inputs.get("vectordbkwargs", {})
        full_kwargs = {**self.search_kwargs, **vectordbkwargs}
        return self.vectorstore.similarity_search(
            question, k=self.top_k_docs_for_context, **full_kwargs
        )