code: def test_mutag(get_dataset):
      dataset = get_dataset(name="MUTAG")
      assert len(dataset) == 188
      assert dataset.num_features == 7
      assert dataset.num_classes == 2
      assert str(dataset) == "MUTAG(188)"
  
      assert len(dataset[0]) == 4
      assert dataset[0].edge_attr.size(1) == 4
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_mutag(get_dataset) without return types