langchain/vectorstores/faiss.py/FAISS/__init__
class FAISS:    def __init__(
        self,
        embedding_function: Callable,
        index: Any,
        docstore: Docstore,
        index_to_docstore_id: Dict[int, str],
        relevance_score_fn: Optional[
            Callable[[float], float]
        ] = _default_relevance_score_fn,
        normalize_L2: bool = False,
    ):
        """Initialize with necessary components."""
        self.embedding_function = embedding_function
        self.index = index
        self.docstore = docstore
        self.index_to_docstore_id = index_to_docstore_id
        self.relevance_score_fn = relevance_score_fn
        self._normalize_L2 = normalize_L2