if search_type not in ("similarity", "hybrid", "semantic_hybrid"):
                raise ValueError(f"search_type of {search_type} not allowed.")
        return values
    def _get_relevant_documents(
        self,
        query: str,
        run_manager: CallbackManagerForRetrieverRun,
        **kwargs: Any,
    ) -> List[Document]:
        if self.search_type == "similarity":
            docs = self.vectorstore.vector_search(query, k=self.k, **kwargs)
        elif self.search_type == "hybrid":
            docs = self.vectorstore.hybrid_search(query, k=self.k, **kwargs)
        elif self.search_type == "semantic_hybrid":
            docs = self.vectorstore.semantic_hybrid_search(query, k=self.k, **kwargs)
        else:
            raise ValueError(f"search_type of {self.search_type} not allowed.")
        return docs
    async def _aget_relevant_documents(
        self,
        query: str,
        *,
        run_manager: AsyncCallbackManagerForRetrieverRun,
    ) -> List[Document]:
        raise NotImplementedError(
            "AzureSearchVectorStoreRetriever does not support async"
        )