def METHOD_NAME():
    data = PaddedBatch(
        payload=torch.tensor([
            [1, 2, 0, 0],
            [3, 4, 5, 6],
            [7, 8, 9, 0],
        ]),
        length=torch.tensor([2, 4, 3]),
    )
    # check shape
    torch.testing.assert_close(data.payload.size(), (3, 4))
    # get first transaction
    torch.testing.assert_close(data.payload[:, 0], torch.tensor([1, 3, 7]))
    # get last transaction
    torch.testing.assert_close(data.payload[torch.arange(3), data.seq_lens - 1], torch.tensor([2, 6, 9]))
    # get all transaction flatten
    torch.testing.assert_close(data.payload[data.seq_len_mask.bool()], torch.tensor([1, 2, 3, 4, 5, 6, 7, 8, 9]))