def __str__(self):
        return yaml.dump(self._root_config, default_flow_style=False, indent=4)
A child has changed its input lists and/or output lists,
dataset/ETHPy150Open coursera/dataduct/dataduct/config/config.py/Config.__str__--crossover with--dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.main/src/openmdao/main/depgraph.py/DependencyGraph.child_config_changed