custom_index (`faiss.Index`, *optional*):
                Custom Faiss index that you already have instantiated and configured for your needs.
            batch_size (`int`):
                Size of the batch to use while adding vectors to the `FaissIndex`. Default value is `1000`.
                <Added version="2.4.0"/>
            train_size (`int`, *optional*):
                If the index needs a training step, specifies how many vectors will be used to train the index.
            faiss_verbose (`bool`, defaults to `False`):
                Enable the verbosity of the Faiss index.
            dtype (`data-type`):
                The dtype of the numpy arrays that are indexed.
                Default is `np.float32`.