@classmethod
def garbage_collect(cls):
    yesterday = (datetime.datetime.now() - datetime.timedelta(hours=24))
    cls.objects.filter(created_at__lt=yesterday).delete()
@classmethod
def garbage_collect(cls):
    yesterday = (datetime.datetime.now() - datetime.timedelta(hours=24))
    cls.objects.filter(created_at__lt=yesterday).delete()