code: def __next__(self):
      if self.counter == self.size:
          raise StopIteration
      value = self.step * self.counter
      self.counter += 1
      return value
  
file_path: pytorch-lightning/tests/tests_data/streaming/test_dataloader.py
imports: import torch
  from lightning.data.streaming import CombinedStreamingDataset, StreamingDataLoader
  from torch import tensor
label_desc: Use image node_id 4 for calling the TestStatefulDataset obj's underlying member method code with example usage: obj.__next__() and returns: value