code: def test_model_dict(self):
      models = {
          "m1": MockModel(MockPosterior()),
          "m2": MockModel(MockPosterior()),
      }
      model_dict = ModelDict(**models)
      self.assertIs(model_dict["m1"], models["m1"])
      self.assertIs(model_dict["m2"], models["m2"])
      with self.assertRaisesRegex(
          InputDataError, "Expected all models to be a BoTorch `Model`."
      ):
          ModelDict(m=MockPosterior())
  
imports: from unittest.mock import patch
  import torch
  from botorch.acquisition.objective import PosteriorTransform
  from botorch.exceptions.errors import InputDataError
  from botorch.models.deterministic import GenericDeterministicModel
  from botorch.models.model import Model, ModelDict, ModelList
  from botorch.models.utils import parse_training_data
  from botorch.posteriors.deterministic import DeterministicPosterior
  from botorch.posteriors.posterior_list import PosteriorList
  from botorch.utils.testing import BotorchTestCase, MockModel, MockPosterior
label_desc: Use image node_id 1 for calling the TestModelDict obj's underlying member method code with example usage: obj.test_model_dict() without return types