def is_series(self):
        copy = list(self.items)
        for k, _ in enumerate(copy):
            try:
                if not self.is_successor(copy[k], copy[k + 1]):
                    yield False
            except __HOLE__:
                continue
        yield True
dataset/ETHPy150Open christabor/MoAL/MOAL/maths/set_theory.py/Set.is_series