code: def __call__(self, x):
      if isinstance(x, int):
          return self.i2s[x]
      else:
          return self.s2i.get(x, self.s2i["<UNK>"])
  
imports: import json
  import pickle
  import random
  import dgl
  import numpy
  import torch
label_desc: Use image node_id 6 for calling the Vocab obj's underlying member method code with example usage: obj.__call__(x) and returns: self, self