code: def get_dummy_sampled_df():
      df = cudf.DataFrame()
      df["sources"] = [0, 0, 1, 0, 0, 1, 0, 0, 2] + [np.nan] * 4
      df["destinations"] = [1, 2, 0, 1, 2, 1, 2, 0, 1] + [np.nan] * 4
      df["batch_id"] = [0, 0, 0, 1, 1, 1, 2, 2, 2] + [np.nan] * 4
      df["hop_id"] = [0, 1, 1, 0, 1, 1, 0, 1, 1] + [np.nan] * 4
      df["map"] = [4, 7, 10, 13, 10, 11, 12, 13, 14, 15, 16, 17, 18]
      df = df.astype("int32")
      df["hop_id"] = df["hop_id"].astype("uint8")
      df["map"] = df["map"].astype("int64")
      return df
  
file_path: cugraph/python/cugraph-dgl/tests/test_utils.py
imports: import cudf
  import cupy
  import numpy
  from cugraph_dgl.dataloading.utils.sampling_helpers import cast_to_tensor, _get_renumber_map, _split_tensor, _get_tensor_d_from_sampled_df, create_homogeneous_sampled_graphs_from_dataframe, _get_source_destination_range, _create_homogeneous_cugraph_dgl_nn_sparse_graph, create_homogeneous_sampled_graphs_from_dataframe_csc
  from cugraph.utilities.utils import import_optional
label_desc: Use image node_id 2 for calling a global function with example usage: get_dummy_sampled_df() and returns: df