def load_pretrain_arrows(root, arrow_paths):
    """
    Args:
        image_dir (str): path to the raw dataset. e.g., "~/coco/train2017".
    Returns:
        list[dict]: a list of dicts in Detectron2 standard format. (See
        `Using Custom Datasets </tutorials/datasets.html>`_ )
    """
    arrs = []
    for arrow_path in arrow_paths:
        arr = pa.ipc.RecordBatchFileReader(
                        pa.memory_map(os.path.join(root, arrow_path), "r")
                    ).read_all()

        arrs.append(arr)
    return arrs

    Args:
        image_dir (str): path to the raw dataset. e.g., "~/coco/train2017".
    Returns:
        list[dict]: a list of dicts in Detectron2 standard format. (See
        `Using Custom Datasets </tutorials/datasets.html>`_ )
    
datasets/registration/register_vlp_datasets.py