text: def compare_models(model1, model2, observed,  truth):
      models = (model1, model2)
      predicted = [model.predict(*observed) for model in models]
      correct = [p==truth for p in predicted]
      idxs = correct[0] & ~correct[1]
      for idx in idxs:
          print(observed[0][idx], observed[1][idx])
          print(model1.diagnostics(idx))
          print(model2.diagnostics(idx))
  