def unicode_test(seg_instance, seg_str):
            seg_gen_str = str(seg_instance)

            self.assertEqual(len(seg_gen_str), 240)
            self.assertEqual(len(seg_str), 240)
            self.assertEqual(seg_gen_str, seg_str)
def days_till_due(self):
        """
        Returns the number of days till the due date. Returns a negative number
        of days when the due date is in the past.
        Returns 0 when the task has no due date.
        """
        due = self.due_date()
        if due:
            diff = due - date.today()
            return diff.days
        return 0