code: def test_featurize():
      """Test that RxnFeaturizer.featurize() correctly featurizes the reactions,
      correctly outputs the input_ids and attention_mask.
      """
      from transformers import RobertaTokenizerFast
      from deepchem.feat.reaction_featurizer import RxnFeaturizer
  
      tokenizer = RobertaTokenizerFast.from_pretrained(
          "seyonec/PubChem10M_SMILES_BPE_450k"
      )
      max_length = 20
      featurizer = RxnFeaturizer(
          tokenizer, sep_reagent=True, max_length=max_length
      )
      reaction = [
          "CCS(=O)(=O)Cl.OCCBr>CCN(CC)CC.CCOCC>CCS(=O)(=O)OCCBr"
      ]
      feats = featurizer.featurize(reaction)
      assert feats.shape == (1, 2, 2, 1, max_length)
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_featurize() without return types