def start_object(self, obj):
        raise NotImplementedError
Given an instance or class, guess if it is or is acting as one of
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/core/serializers/base.py/Serializer.start_object--crossover with--dataset/ETHPy150Open ralfonso/theory/theory/model/mpdutil.py/duck_type_collection