def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def __init__(
        self, minimum=None, maximum=None, choices=None, optional=False
    ):
        self._required = not optional
        self._minimum = minimum
        self._maximum = maximum
        self._choices = choices