code: def _load_sampled_file(dataset_obj, fn, skip_rename=False):
      df = cudf.read_parquet(os.path.join(fn))
      if dataset_obj.edge_dir == "in" and not skip_rename:
          df.rename(
              columns={
                  "sources": "destinations",
                  "destinations": "sources",
              },
              inplace=True,
          )
      dataset_obj._current_batch_fn = fn
      return df
  
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 1 for calling a global function with example usage: _load_sampled_file(dataset_obj, fn, skip_rename) and returns: df