code: def __init__(self):
      self.dataset = list(range(0, DATA_SIZE))
  
imports: import time
  import unittest
  import json
  import os
  import random
  from pgl.utils.data.dataset import Dataset, StreamDataset
  from pgl.utils.data.dataloader import Dataloader
label_desc: Use image node_id 1 to create a new IterDataset object from inherited base classes: StreamDataset with example: obj = IterDataset()