def METHOD_NAME(self):
    """
    Return a list of valid batch shapes, for example::
        [(8, 512), (16, 256), (32, 128)]
    The first dimension of each tuple is the batch size and can be ``None``
    to automatically infer the max batch size based on ``--max-tokens``.
    The second dimension of each tuple is the max supported length as given
    by :func:`fairseq.data.FairseqDataset.num_tokens`.
    This will be used by :func:`fairseq.data.FairseqDataset.batch_by_size`
    to restrict batch shapes. This is useful on TPUs to avoid too many
    dynamic shapes (and recompilations).
    """
    return None