code: def __len__(self):
      return self.num_batches
  
imports: from __future__ import annotations
  from typing import Tuple, Dict, Optional, List, Union
  import os
  import cudf
  from cugraph.utilities.utils import import_optional
  from cugraph_dgl.dataloading.utils.sampling_helpers import create_homogeneous_sampled_graphs_from_dataframe, create_heterogeneous_sampled_graphs_from_dataframe, create_homogeneous_sampled_graphs_from_dataframe_csc
label_desc: Use image node_id 2 for calling the HomogenousBulkSamplerDataset obj's underlying member method code with example usage: obj.__len__() and returns: self