class_docstr: GAN Dataset searchs for all the wav files under root path
  and converts them to acoustic features on the fly and returns
  random segments of (audio, feature) couples.
code: def shuffle_mapping(self):
      random.shuffle(self.G_to_D_mappings)
  
file_path: TTS/TTS/vocoder/datasets/gan_dataset.py
imports: import os
  import glob
  import torch
  import random
  import numpy
  from torch.utils.data import Dataset
  from multiprocessing import Manager
label_desc: Use image node_id 6 for calling the GANDataset obj's underlying member method code with example usage: obj.shuffle_mapping() without return types