code: def _flip(samples):
      sentence = samples["text_input"]
      image0, image1 = samples["image0"], samples["image1"]
  
      if "left" not in sentence and "right" not in sentence:
          if random.random() < 0.5:
              image0, image1 = image1, image0
      else:
          if random.random() < 0.5:
              sentence = sentence.replace("left", "[TEMP_TOKEN]")
              sentence = sentence.replace("right", "left")
              sentence = sentence.replace("[TEMP_TOKEN]", "right")
  
              image0, image1 = image1, image0
  
      samples["text_input"] = sentence
      samples["image0"] = image0
      samples["image1"] = image1
  
      return samples
  
file_path: lavis/lavis/datasets/datasets/nlvr_datasets.py
imports: import os
  import random
  from collections import OrderedDict
  from lavis.datasets.datasets.multimodal_classification_datasets import MultimodalClassificationDataset
  from PIL import Image
label_desc: Use image node_id 3 for calling the NLVRDataset obj's underlying member method code with example usage: obj._flip(samples) and returns: samples