code: def update(self, token):
      if isinstance(token, list):
          for t in token:
              self.update(t)
      else:
          self.wf[token] = self.wf.get(token, 0) + 1
  
imports: import json
  import pickle
  import random
  import dgl
  import numpy
  import torch
label_desc: Use image node_id 4 for calling the Vocab obj's underlying member method code with example usage: obj.update(token) without return types