def METHOD_NAME(self):
    for a, b in [
            ([0],                 [0]),
            ([0, 0],              [0]),
            ([3, 7],              [3, 7]),
            ([3, 7, 7],           [3, 7]),
            ([3, 3, 7, 7, 7],     [7]),
            ([3, 3, 3, 7, 7],     [3, 7]),
            ([0, 0, 2, 2],        [2]),
            ([0, 2, 2, 2, 2, 3],  [0, 3]),
            ([0, 0, 0, 1, 1, 2, 2, 2, 3, 4, 4, 4, 4, 5],
             [0, 2, 3, 5]),
        ]:
        s = BitArray()
        s.flips = a
        s._reduce()
        self.assertEqual(s.flips, b)