code: def pad(self, minibatch):
      if isinstance(minibatch[0][0], list):
          self.fix_length = max(
              max(len(x) for x in ex) for ex in minibatch
          )
          padded = []
          for ex in minibatch:
              # sentences are indexed in reverse order and truncated to memory_size
              nex = ex[::-1][: self.memory_size]
              padded.append(
                  super(BABI20Field, self).pad(nex)
                  + [[self.pad_token] * self.fix_length]
                  * (self.memory_size - len(nex))
              )
          self.fix_length = None
          return padded
      else:
          return super(BABI20Field, self).pad(minibatch)
  
file_path: pytext/pytext/legacy/datasets/babi.py
imports: import os
  from io import open
  import torch
  from ..data import Dataset, Example, Field, Iterator
label_desc: Use image node_id 3 for calling the BABI20Field obj's underlying member method code with example usage: obj.pad(minibatch) and returns: padded, super