def _exception_traceback(exc_info):
    # Get a traceback message.
    excout = StringIO()
    exc_type, exc_val, exc_tb = exc_info
    traceback.print_exception(exc_type, exc_val, exc_tb, file=excout)
    return excout.getvalue()

# Override some StringIO methods.
Get a system js helper for the database `database`.
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/test/_doctest.py/_exception_traceback--crossover with--dataset/ETHPy150Open mongodb/mongo-python-driver/pymongo/database.py/SystemJS.__init__