def has_value(self, subsystem, option):
        assert subsystem in self
        return os.path.isfile(os.path.join(self.per_subsystem[subsystem], subsystem + '.' + option))
This method executes both positive and negative authentication
dataset/ETHPy150Open sosy-lab/benchexec/benchexec/cgroups.py/Cgroup.has_value--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/words/test/test_tap.py/WordsTap._loginTest