def failIfIdentical(self, first, second, msg=None):
        if first is second:
            raise self.failureException(msg or '%r is %r' % (first, second))
        return first
Given a Query, create a cache key.
dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/trial/unittest.py/_Assertions.failIfIdentical--crossover with--dataset/ETHPy150Open zzzeek/sqlalchemy/examples/dogpile_caching/caching_query.py/_key_from_query