def __init__(self, data, bsz, bptt, device="cpu", ext_len=None):
        """
        data -- LongTensor -- the LongTensor is strictly ordered
        """
        self.bsz = bsz
        self.bptt = bptt
        self.ext_len = ext_len if ext_len is not None else 0

        self.device = device

        # Work out how cleanly we can divide the dataset into bsz parts.
        self.n_step = data.size(0) // bsz

        # Trim off any extra elements that wouldn't cleanly fit (remainders).
        data = data.narrow(0, 0, self.n_step * bsz)

        # Evenly divide the data across the bsz batches.
        self.data = data.view(bsz, -1).t().contiguous().to(device)

        # Number of mini-batches
        self.n_batch = (self.n_step + self.bptt - 1) // self.bptt

        data -- LongTensor -- the LongTensor is strictly ordered
        
dpkd/transformers/src/transformers/models/transfo_xl/tokenization_transfo_xl.py