class_docstr: Test RdkitGridFeaturizer class defined in rdkit_grid_featurizer module.
code: def test_example_featurizer(self):
      # check if use-case from examples works
      featurizer = RdkitGridFeaturizer(
          voxel_width=1.0,
          box_width=75.0,
          feature_types=["ecfp", "splif", "hbond", "salt_bridge"],
          ecfp_power=9,
          splif_power=9,
          flatten=True,
      )
      feature_tensor = featurizer.featurize(
          [(self.ligand_file, self.protein_file)]
      )
      self.assertIsInstance(feature_tensor, np.ndarray)
  
file_path: deepchem/deepchem/feat/tests/test_rdkit_grid_features.py
imports: import os
  import unittest
  import numpy
  from deepchem.feat import RdkitGridFeaturizer
label_desc: Use image node_id 3 for calling the TestRdkitGridFeaturizer obj's underlying member method code with example usage: obj.test_example_featurizer() without return types