def __init__(self, *args, **kwargs):
        assert kwargs.get('primary_key', False) is True, \
               self.__class__.__name__ % "%ss must have primary_key=True."
        kwargs['blank'] = True
        Field.__init__(self, *args, **kwargs)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/db/models/fields/__init__.py/AutoField.__init__/swapped operands of `%`