code: def __getitem__(self, index):
      if index > self.l:
          raise IndexError()
      return (index, np.sin(np.array([index])).view("<u1"))
  
imports: from collections import defaultdict
  from tempfile import TemporaryDirectory
  from os import path
  from typing import Counter
  import pytest
  from assertpy import assert_that
  import numpy
  from torch.utils.data import Dataset, distributed
  from torch.multiprocessing import spawn, Queue
  from torch.distributed import init_process_group
  from ffcv.loader.loader import ORDER_TYPE, OrderOption
  from ffcv.writer import DatasetWriter
  from ffcv.fields import IntField, BytesField
  from ffcv import Loader
label_desc: Use image node_id 3 for calling the DummyDataset obj's underlying member method code with example usage: obj.__getitem__(index) and returns: index,  np