code: def hetero_model():
      return HeteroSAGE
  
file_path: pytorch_geometric/test/explain/conftest.py
imports: from typing import Optional
  import pytest
  import torch
  from torch_geometric.data import Data, HeteroData
  from torch_geometric.explain import Explanation
  from torch_geometric.explain.config import MaskType
  from torch_geometric.nn import SAGEConv, to_hetero
  from torch_geometric.testing import get_random_edge_index
label_desc: Use image node_id 3 for calling a global function with example usage: hetero_model() and returns: HeteroSAGE