code: def test_internal_external_key_conversion():
      assert ParameterDict.to_internal_key("a.b") == "a#b"
      assert ParameterDict.to_internal_key("ab") == "ab"
      assert ParameterDict.to_internal_key("a.b.c") == "a#b#c"
      assert ParameterDict.to_internal_key(("a", "b")) == "<a___b>"
      assert ParameterDict.to_internal_key(("a.b", "c")) == "<a#b___c>"
      assert ParameterDict.to_internal_key("type") == "<type>"
  
      assert ParameterDict.to_external_key("a#b") == "a.b"
      assert ParameterDict.to_external_key("a#b#c") == "a.b.c"
      assert ParameterDict.to_external_key("<a___b>") == ("a", "b")
      assert ParameterDict.to_external_key("<a#b___c>") == ("a.b", "c")
      assert ParameterDict.to_external_key("<type>") == "type"
  
imports: import torch
  from torch_geometric.nn.parameter_dict import ParameterDict
label_desc: Use image node_id 1 for calling a global function with example usage: test_internal_external_key_conversion() without return types