def METHOD_NAME(self) -> None:
    # transformers are sorted by the dependent order
    transformers = self._generate_transformers_runbook(3)
    transformers[0].depends_on = ["t1", "t2"]
    transformers[1].depends_on = ["t2"]
    transformers = transformer._sort(transformers)
    self.assertEqual("t2", transformers[0].name)
    self.assertEqual("t1", transformers[1].name)
    self.assertEqual("t0", transformers[2].name)