code: def to_internal_key(cls, key: Key) -> str:
      if isinstance(
          key, tuple
      ):  # ParameterDict can't handle tuples as keys
          assert len(key) > 1
          key = f"<{'___'.join(key)}>"
      assert isinstance(key, str)
  
      # ParameterDict cannot handle keys that exists as class attributes:
      if key in cls.CLASS_ATTRS:
          key = f"<{key}>"
  
      # ParameterDict cannot handle dots in keys:
      return key.replace(".", "#")
  
file_path: pytorch_geometric/torch_geometric/nn/parameter_dict.py
imports: from typing import Final, Iterable, Mapping, Optional, Set, Tuple, Union
  import torch
  from torch.nn import Parameter
label_desc: Use image node_id 2 for calling the ParameterDict obj's underlying member method code with example usage: obj.to_internal_key(cls, key) and returns: key