def METHOD_NAME(num_workers=4):
    mean_rgb = [123.68, 116.779, 103.939]
    std_rgb = [58.393, 57.12, 57.375]
    def batch_fn(batch):
        return batch.data[0].asnumpy(), batch.label[0].asnumpy()
    img_size = 299 if model_name == "inceptionv3" else 224
    val_data = mx.io.ImageRecordIter(
        path_imgrec=calibration_rec,
        preprocess_threads=num_workers,
        shuffle=False,
        batch_size=batch_size,
        resize=256,
        data_shape=(3, img_size, img_size),
        mean_r=mean_rgb[0],
        mean_g=mean_rgb[1],
        mean_b=mean_rgb[2],
        std_r=std_rgb[0],
        std_g=std_rgb[1],
        std_b=std_rgb[2],
    )
    return val_data, batch_fn