code: def test_compose():
      transform = T.Compose([T.Center(), T.AddSelfLoops()])
      assert str(transform) == (
          "Compose([\n" "  Center(),\n" "  AddSelfLoops()\n" "])"
      )
  
      pos = torch.tensor([[0.0, 0.0], [2.0, 0.0], [4.0, 0.0]])
      edge_index = torch.tensor([[0, 1, 1, 2], [1, 0, 2, 1]])
  
      data = Data(edge_index=edge_index, pos=pos)
      data = transform(data)
      assert len(data) == 2
      assert data.pos.tolist() == [[-2.0, 0.0], [0.0, 0.0], [2.0, 0.0]]
      assert data.edge_index.size() == (2, 7)
  
imports: import torch
  import torch_geometric.transforms
  from torch_geometric.data import Data
label_desc: Use image node_id 1 for calling a global function with example usage: test_compose() without return types