metric_type (`int`, *optional*):
                Type of metric. Ex: `faiss.faiss.METRIC_INNER_PRODUCT` or `faiss.METRIC_L2`.
            custom_index (`faiss.Index`, *optional*):
                Custom Faiss index that you already have instantiated and configured for your needs.
            batch_size (`int`, *optional*):
                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 (`numpy.dtype`):
                The dtype of the numpy arrays that are indexed. Default is np.float32.
        """
        super().add_faiss_index_from_external_arrays(
            external_arrays=external_arrays.astype(dtype),