code: def test_register():
      assert len(register.act_dict) == 8
      assert list(register.act_dict.keys()) == [
          "relu",
          "selu",
          "prelu",
          "elu",
          "lrelu_01",
          "lrelu_025",
          "lrelu_05",
          "identity",
      ]
      assert str(register.act_dict["relu"]()) == "ReLU()"
  
      register.register_act("lrelu_03", torch.nn.LeakyReLU(0.3))
      assert len(register.act_dict) == 9
      assert "lrelu_03" in register.act_dict
  
imports: import torch
  import torch_geometric.graphgym.register
  from torch_geometric.testing import withPackage
label_desc: Use image node_id 2 for calling a global function with example usage: test_register() without return types