def __init__(self, attribute):
    self.attribute = attribute
    self.categories = dict([(x, {}) for x in self.active_days])
Return DDP change message of specified type (msg) for obj.
dataset/ETHPy150Open google/grr/grr/lib/flows/cron/system.py/_ActiveCounter.__init__--crossover with--dataset/ETHPy150Open django-ddp/django-ddp/dddp/api.py/Collection.obj_change_as_msg