class_docstr: A helper class to construct serializable edge types by merging an edge
  type tuple into a single string.
class_docstr_tok: ["A","helper","class","to","construct","serializable","edge","types","by","merging","an","edge","type","tuple","into","a","single","string","."]
docstr: Returns the original edge type.
docstr_tok: ["Returns","the","original","edge","type","."]
code: def to_tuple(self) -> EdgeType:
      r"""Returns the original edge type."""
      out = tuple(self.split(EDGE_TYPE_STR_SPLIT))
      if len(out) != 3:
          raise ValueError(
              f"Cannot convert the edge type '{self}' to a "
              f"tuple since it holds invalid characters"
          )
      return out
  
file_path: pytorch_geometric/torch_geometric/typing.py
imports: import inspect
  import os
  import sys
  import warnings
  from typing import Any, Dict, List, Optional, Tuple, Union
  import numpy
  import torch
  from torch import Tensor
label_desc: Use image node_id 2 for calling the EdgeTypeStr obj's underlying member method code with example usage: obj.to_tuple() and returns: out