code: def get_index(self, smiles):
      return self.vmap[smiles]
  
file_path: DIG/dig/ggraph/method/JTVAE/fast_jtnn/vocab.py
imports: import rdkit
  import rdkit.Chem
  import copy
label_desc: Use image node_id 2 for calling the Vocab obj's underlying member method code with example usage: obj.get_index(smiles) and returns: self