code: def __len__(self) -> int:
      return len(self.windows)
  
file_path: gluonts/src/gluonts/nursery/daf/tslib/dataset/windows.py
imports: from __future__ import annotations
  from typing import Optional, List, Tuple, Any
  from itertools import repeat
  from torch.utils.data import Dataset
  from tqdm import tqdm
  import numpy
  from .timeseries import TimeSeries, TimeSeriesCorpus
label_desc: Use image node_id 2 for calling the WindowsDataset obj's underlying member method code with example usage: obj.__len__() and returns: len