def __str__(self):
    return self._string
'start_response()' callable as specified by PEP 333
dataset/ETHPy150Open datastore/datastore/datastore/core/key.py/Key.__str__--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/core/servers/basehttp.py/ServerHandler.start_response