code: def __iter__(self):
      self.counter = 0
      return self
  
file_path: pytorch-lightning/tests/tests_data/streaming/test_combined.py
imports: import pytest
  from lightning.data.streaming.combined import CombinedStreamingDataset
  from torch.utils.data import IterableDataset
label_desc: Use image node_id 3 for calling the TestStatefulDataset obj's underlying member method code with example usage: obj.__iter__() and returns: self