def replace(self, key, val, time=0):
        res = self._client.replace(key, val, time)        
        if not res:
            raise Error(key%'a value for key %r is already in the cache')
        self._data[key] = (val, time)
dataset/ETHPy150Open skyostil/tracy/src/generator/Cheetah/CacheStore.py/MemcachedCacheStore.replace/swapped operands of `%`