code: def __getitem__(self, idx):
      return [self.dataset[subidx] for subidx in self.batches[idx]]
  
imports: import os
  import random
  import torch
  import torchaudio
  from pytorch_lightning import LightningDataModule
label_desc: Use image node_id 2 for calling the CustomBucketDataset obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: unknown