code: def testBadInputOrOutputError(self):
      class UnitQ(pipeline.Pipeline):
          def __init__(self, name="UnitQ"):
              pipeline.Pipeline.__init__(self, Type0, Type1, name)
  
          def transform(self, input_object):
              pass
  
      class UnitR(pipeline.Pipeline):
          def __init__(self):
              pipeline.Pipeline.__init__(self, Type1, Type0)
  
          def transform(self, input_object):
              pass
  
      # Missing Input.
      q, r = UnitQ(), UnitR()
      dag = {r: q, dag_pipeline.DagOutput("output"): r}
      with self.assertRaises(dag_pipeline.BadInputOrOutputError):
          dag_pipeline.DAGPipeline(dag)
  
      # Missing Output.
      dag = {q: dag_pipeline.DagInput(Type0), r: q}
      with self.assertRaises(dag_pipeline.BadInputOrOutputError):
          dag_pipeline.DAGPipeline(dag)
  
      # Multiple instances of Input with the same type IS allowed.
      q2 = UnitQ("UnitQ2")
      dag = {
          q: dag_pipeline.DagInput(Type0),
          q2: dag_pipeline.DagInput(Type0),
          dag_pipeline.DagOutput(): {"q": q, "q2": q2},
      }
      _ = dag_pipeline.DAGPipeline(dag)
  
      # Multiple instances with different types is not allowed.
      dag = {
          q: dag_pipeline.DagInput(Type0),
          r: dag_pipeline.DagInput(Type1),
          dag_pipeline.DagOutput(): {"q": q, "r": r},
      }
      with self.assertRaises(dag_pipeline.BadInputOrOutputError):
          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 15 for calling the DAGPipelineTest obj's underlying member method code with example usage: obj.testBadInputOrOutputError() without return types