code: def test_tuple_keys():
      module_dict = ModuleDict(
          {
              ("a", "b"): torch.nn.Linear(16, 16),
              ("a.b", "c"): torch.nn.Linear(8, 8),
          }
      )
  
      expected_keys = {("a", "b"), ("a.b", "c")}
      assert set(module_dict.keys()) == expected_keys
      assert (
          set([key for key, _ in module_dict.items()]) == expected_keys
      )
  
      for key in expected_keys:
          assert key in module_dict
  
      del module_dict["a", "b"]
      assert ("a", "b") not in module_dict
  
imports: import torch
  from torch_geometric.nn.module_dict import ModuleDict
label_desc: Use image node_id 3 for calling a global function with example usage: test_tuple_keys() without return types