code: def test_featurizer_smiles(self):
      try:
          from rdkit import Chem
      except ModuleNotFoundError:
          raise ImportError(
              "This method requires RDKit to be installed."
          )
  
      smiles = [
          "Cc1ccccc1CO",
          "CC1CCC(C)C(N)C1",
          "CCC(N)=O",
          "Fc1cccc(F)c1",
          "CC(C)F",
          "C1COC2NCCC2C1",
          "C1=NCc2ccccc21",
      ]
  
      invalid_smiles = ["axa", "xyz", "inv"]
  
      featurizer = MolGanFeaturizer()
      valid_data = featurizer.featurize(smiles)
      invalid_data = featurizer.featurize(invalid_smiles)
  
      # test featurization
      valid_graphs = list(
          filter(lambda x: isinstance(x, GraphMatrix), valid_data)
      )
      invalid_graphs = list(
          filter(lambda x: not isinstance(x, GraphMatrix), invalid_data)
      )
      assert len(valid_graphs) == len(smiles)
      assert len(invalid_graphs) == len(invalid_smiles)
  
      # test defeaturization
      valid_mols = featurizer.defeaturize(valid_graphs)
      invalid_mols = featurizer.defeaturize(invalid_graphs)
      valid_mols = list(
          filter(lambda x: isinstance(x, Chem.rdchem.Mol), valid_mols)
      )
      invalid_mols = list(
          filter(
              lambda x: not isinstance(x, Chem.rdchem.Mol), invalid_mols
          )
      )
      assert len(valid_graphs) == len(valid_mols)
      assert len(invalid_graphs) == len(invalid_mols)
  
      mols = list(map(Chem.MolFromSmiles, smiles))
      redone_smiles = list(map(Chem.MolToSmiles, mols))
      # sanity check; see if something weird does not happen with rdkit
      assert redone_smiles == smiles
  
      # check if original smiles match defeaturized smiles
      defe_smiles = list(map(Chem.MolToSmiles, valid_mols))
      assert defe_smiles == smiles
  
imports: import unittest
  from deepchem.feat.molecule_featurizers import MolGanFeaturizer
  from deepchem.feat.molecule_featurizers import GraphMatrix
label_desc: Use image node_id 1 for calling the TestMolganFeaturizer obj's underlying member method code with example usage: obj.test_featurizer_smiles() without return types