def as_retriever(self, **kwargs: Any) -> BaseRetriever:
        """Return a Retriever for this managed index."""
        from llama_index.indices.managed.vertexai.retriever import (
            VertexAIRetriever,
        )

        similarity_top_k = kwargs.pop("similarity_top_k", None)
        vector_distance_threshold = kwargs.pop("vector_distance_threshold", None)

        return VertexAIRetriever(
            self.corpus_name,
            similarity_top_k,
            vector_distance_threshold,
            self._user_agent,
            **kwargs,
        )
Return a Retriever for this managed index.
llama-index-integrations/indices/llama-index-indices-managed-vertexai/llama_index/indices/managed/vertexai/base.py