code: def test_sampled_subgraph_impl_representation_hetero():
      sampled_subgraph_impl = SampledSubgraphImpl(
          sampled_csc={
              "n1:e1:n2": gb.CSCFormatBase(
                  indptr=torch.tensor([0, 2, 4]),
                  indices=torch.tensor([4, 5, 6, 7]),
              ),
              "n2:e2:n1": gb.CSCFormatBase(
                  indptr=torch.tensor([0, 2, 4, 6, 8]),
                  indices=torch.tensor([2, 3, 4, 5, 6, 7, 8, 9]),
              ),
          },
          original_column_node_ids={
              "n1": torch.tensor([1, 0, 0, 1]),
              "n2": torch.tensor([1, 2]),
          },
          original_row_node_ids={
              "n1": torch.tensor([1, 0, 0, 1, 1, 0, 0, 1]),
              "n2": torch.tensor([1, 2, 0, 1, 0, 2, 0, 2, 0, 1]),
          },
          original_edge_ids=None,
      )
      expected_result = str(
          """SampledSubgraphImpl(sampled_csc={'n1:e1:n2': CSCFormatBase(indptr=tensor([0, 2, 4]),
                                               indices=tensor([4, 5, 6, 7]),
                                 ), 'n2:e2:n1': CSCFormatBase(indptr=tensor([0, 2, 4, 6, 8]),
                                               indices=tensor([2, 3, 4, 5, 6, 7, 8, 9]),
                                 )},
                     original_row_node_ids={'n1': tensor([1, 0, 0, 1, 1, 0, 0, 1]), 'n2': tensor([1, 2, 0, 1, 0, 2, 0, 2, 0, 1])},
                     original_edge_ids=None,
                     original_column_node_ids={'n1': tensor([1, 0, 0, 1]), 'n2': tensor([1, 2])},
  )"""
      )
      assert str(sampled_subgraph_impl) == expected_result, print(
          sampled_subgraph_impl
      )
  
file_path: dgl/tests/python/pytorch/graphbolt/impl/test_sampled_subgraph_impl.py
imports: import unittest
  import backend
  import dgl.graphbolt
  import pytest
  import torch
  from dgl.graphbolt.impl.sampled_subgraph_impl import SampledSubgraphImpl
label_desc: Use image node_id 8 for calling a global function with example usage: test_sampled_subgraph_impl_representation_hetero() without return types