def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def is_active(self):
        """
        Returns True when the start date is today or in the past and the
        task has not yet been completed.
        """
        start = self.start_date()
        return not self.is_completed() and (not start or start <= date.today())