def append(self, value, sig):
        assert isinstance(sig, tuple), (value, sig)
        self.versions.append((sig, value))
Call all extension drivers during PC update.
dataset/ETHPy150Open numba/numba/numba/targets/base.py/OverloadSelector.append--crossover with--dataset/ETHPy150Open openstack/group-based-policy/gbpservice/neutron/services/grouppolicy/extension_manager.py/ExtensionManager.process_update_policy_classifier