If the whitespace normalization flag is used, then
                differences in whitespace are ignored.
                    >>> print(list(range(30))) #doctest: +NORMALIZE_WHITESPACE
                    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
                     15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
                     27, 28, 29]
            )