code: def dgl_graph():
      graph_data = {
          ("nt.a", "connects", "nt.b"): (
              th.tensor([0, 1, 2]),
              th.tensor([0, 1, 2]),
          ),
          ("nt.a", "connects", "nt.c"): (
              th.tensor([0, 1, 2]),
              th.tensor([0, 1, 2]),
          ),
          ("nt.c", "connects", "nt.c"): (
              th.tensor([1, 3, 4, 5]),
              th.tensor([0, 0, 0, 0]),
          ),
      }
      g = dgl.heterograph(graph_data)
      return g
  
file_path: cugraph/python/cugraph-dgl/tests/test_cugraph_storage.py
imports: import pytest
  from cugraph.utilities.utils import import_optional
  import cudf
  import numpy
  from cugraph_dgl import CuGraphStorage
  from .utils import assert_same_sampling_len
label_desc: Use image node_id 1 for calling a global function with example usage: dgl_graph() and returns: g