def METHOD_NAME(self):
    class CustomTransformer(TreeForestTransformer):
        def bc(self, data):
            return Discard
        def D(self, node):
            return Discard
    class TreeChecker(Transformer):
        def bc(self, children):
            assert False
        def D(self, token):
            assert False
    tree = CustomTransformer(resolve_ambiguity=False).transform(self.forest)
    TreeChecker(visit_tokens=True).transform(tree)