code: def __init__(self, dataloader_head, dataloader_tail):
      self.iterator_head = self.one_shot_iterator(dataloader_head)
      self.iterator_tail = self.one_shot_iterator(dataloader_tail)
      self.step = 0
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import torch
  from torch.utils.data import Dataset
label_desc: Use image node_id 1 to create a new BidirectionalOneShotIterator object from inherited base classes: object with example: obj = BidirectionalOneShotIterator(dataloader_head, dataloader_tail)