ext_multiple* is ``True``, *fillvalue* will be emitted until the
    number of items emitted is a multiple of *n*::

        >>> list(padded([1, 2, 3, 4], n=3, next_multiple=True))
        [1, 2, 3, 4, None, None]

    If *n* is ``None``, *fillvalue* will be emitted indefinitely.

    Nr"