code: def __getitem__(self, index):
      assert 0 <= index < self.length
      return pd.DataFrame(
          np.random.randint(0, 100, size=(index + 1, 4)),
          columns=list("ABCD"),
      )
  
file_path: qlib/tests/rl/test_data_queue.py
imports: import multiprocessing
  import time
  import numpy
  import pandas
  from torch.utils.data import Dataset, DataLoader
  from qlib.rl.utils.data_queue import DataQueue
label_desc: Use image node_id 2 for calling the DummyDataset obj's underlying member method code with example usage: obj.__getitem__(index) and returns: pd