code: def test_gcn_conv_error():
      with pytest.raises(
          ValueError, match="does not support adding self-loops"
      ):
          GCNConv(16, 32, normalize=False, add_self_loops=True)
  
file_path: pytorch_geometric/test/nn/conv/test_gcn_conv.py
imports: import pytest
  import torch
  import torch_geometric.typing
  from torch_geometric.nn import GCNConv
  from torch_geometric.nn.conv.gcn_conv import gcn_norm
  from torch_geometric.testing import is_full_test
  from torch_geometric.typing import WITH_PT21, SparseTensor
  from torch_geometric.utils import to_torch_coo_tensor, to_torch_csc_tensor
label_desc: Use image node_id 5 for calling a global function with example usage: test_gcn_conv_error() without return types