def test_contains(self):
        prio_set_list = event._PrioritizedSetList()
        obj = object()

        prio_set_list.add(0, obj)
        assert obj in prio_set_list
def set_submodule(self, submodule: 'Submodule') -> None:
        """Set this instance's submodule. It must be called before
        the first write operation begins"""
        self._smref = weakref.ref(submodule)