```python
def _init_libset(self):
         self._libset = [clazz() for clazz in self._libset_classes]
```

Since you're using lists, not sets, you can just do:
```python
def HealingCertManager(BaseCertManager):
      _libset_classes = [entCertLib, installedProdLib, healinglib, entCertLib]
```