code: def testInvalidDAGError(self):
      class UnitQ(pipeline.Pipeline):
          def __init__(self):
              pipeline.Pipeline.__init__(
                  self, Type0, {"a": Type1, "b": Type2}
              )
  
          def transform(self, input_object):
              pass
  
      class UnitR(pipeline.Pipeline):
          def __init__(self):
              pipeline.Pipeline.__init__(self, Type1, Type2)
  
          def transform(self, input_object):
              pass
  
      q, r = UnitQ(), UnitR()
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          UnitR: q,
          dag_pipeline.DagOutput("output"): r,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          "r": q,
          dag_pipeline.DagOutput("output"): r,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          r: UnitQ,
          dag_pipeline.DagOutput("output"): r,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          r: 123,
          dag_pipeline.DagOutput("output"): r,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          dag_pipeline.DagInput(Type0): q,
          dag_pipeline.DagOutput(): q,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          q: dag_pipeline.DagOutput("output"),
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          r: {"abc": q["a"], "def": 123},
          dag_pipeline.DagOutput("output"): r,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
      dag = {
          q: dag_pipeline.DagInput(Type0),
          r: {123: q["a"]},
          dag_pipeline.DagOutput("output"): r,
      }
      with self.assertRaises(dag_pipeline.InvalidDAGError):
          dag_pipeline.DAGPipeline(dag)
  
imports: import collections
  from absl.testing import absltest
  from magenta.pipelines import dag_pipeline
  from magenta.pipelines import pipeline
  from magenta.pipelines import statistics
label_desc: Use image node_id 11 for calling the DAGPipelineTest obj's underlying member method code with example usage: obj.testInvalidDAGError() without return types