text: import pytest
  
  import dice_ml
  from dice_ml.utils import helpers
  
  
  class TestBaseModelLoader:
      def _get_model(self, backend):
          ML_modelpath = helpers.get_adult_income_modelpath(backend=backend)
          m = dice_ml.Model(model_path=ML_modelpath, backend=backend)
          return m
  
      def test_tf(self):
          tf = pytest.importorskip("tensorflow")
          backend = 'TF'+tf.__version__[0]
          m = self._get_model(backend)
          assert issubclass(type(m), dice_ml.model_interfaces.base_model.BaseModel)
          assert isinstance(m, dice_ml.model_interfaces.keras_tensorflow_model.KerasTensorFlowModel)
  
      def test_pyt(self):
          pyt = pytest.importorskip("torch")
          backend = 'PYT'
          m = self._get_model(backend)
          assert issubclass(type(m), dice_ml.model_interfaces.base_model.BaseModel)
          assert isinstance(m, dice_ml.model_interfaces.pytorch_model.PyTorchModel)
  
      def test_sklearn(self):
          pyt = pytest.importorskip("sklearn")
          backend = 'sklearn'
          m = self._get_model(backend)
          assert isinstance(m, dice_ml.model_interfaces.base_model.BaseModel)
  