def split_page(encoded_inputs, max_seq_len=512):
    """
    truncate is often used in training process
    """
    for key in encoded_inputs:
        if key == 'entities':
            encoded_inputs[key] = [encoded_inputs[key]]
            continue
        # encoded_inputs[key] = paddle.to_tensor(encoded_inputs[key])
        encoded_inputs[key] = torch.as_tensor(encoded_inputs[key])
        if encoded_inputs[key].ndim <= 1:  # for input_ids, att_mask and so on
            encoded_inputs[key] = encoded_inputs[key].reshape([-1, max_seq_len])
        else:  # for bbox
            encoded_inputs[key] = encoded_inputs[key].reshape(
                [-1, max_seq_len, 4])
    return encoded_inputs
truncate is often used in training process
ptstructure/vqa/vqa_utils.py