code: def test_radius_graph():
      assert str(RadiusGraph(r=1)) == "RadiusGraph(r=1)"
  
      pos = torch.tensor(
          [
              [0.0, 0.0],
              [1.0, 0.0],
              [2.0, 0.0],
              [0.0, 1.0],
              [-2.0, 0.0],
              [0.0, -2.0],
          ]
      )
  
      data = Data(pos=pos)
      data = RadiusGraph(r=1.5)(data)
      assert len(data) == 2
      assert data.pos.tolist() == pos.tolist()
      assert coalesce(data.edge_index).tolist() == [
          [0, 0, 1, 1, 1, 2, 3, 3],
          [1, 3, 0, 2, 3, 1, 0, 1],
      ]
  
imports: import torch
  from torch_geometric.data import Data
  from torch_geometric.testing import withPackage
  from torch_geometric.transforms import RadiusGraph
  from torch_geometric.utils import coalesce
label_desc: Use image node_id 1 for calling a global function with example usage: test_radius_graph() without return types