code: def test_distance():
      assert str(Distance()) == "Distance(norm=True, max_value=None)"
  
      pos = torch.tensor([[-1.0, 0.0], [0.0, 0.0], [2.0, 0.0]])
      edge_index = torch.tensor([[0, 1, 1, 2], [1, 0, 2, 1]])
      edge_attr = torch.tensor([1.0, 1.0, 1.0, 1.0])
  
      data = Data(edge_index=edge_index, pos=pos)
      data = Distance(norm=False)(data)
      assert len(data) == 3
      assert data.pos.tolist() == pos.tolist()
      assert data.edge_index.tolist() == edge_index.tolist()
      assert data.edge_attr.tolist() == [[1.0], [1.0], [2.0], [2.0]]
  
      data = Data(edge_index=edge_index, pos=pos, edge_attr=edge_attr)
      data = Distance(norm=True)(data)
      assert len(data) == 3
      assert data.pos.tolist() == pos.tolist()
      assert data.edge_index.tolist() == edge_index.tolist()
      assert data.edge_attr.tolist() == [
          [1.0, 0.5],
          [1.0, 0.5],
          [1.0, 1.0],
          [1.0, 1.0],
      ]
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_distance() without return types