code: def split_key(key: str) -> Tuple[str, str]:
      """Split a key into word and sense, e.g. ("usage example", "NOUN").
  
      key (unicode): The key to split.
      RETURNS (tuple): The split (word, sense) tuple.
      """
      if not isinstance(key, str) or "|" not in key:
          raise ValueError(f"Invalid key: {key}")
      word, sense = key.replace("_", " ").rsplit("|", 1)
      return word, sense
  
file_path: sense2vec/sense2vec/util.py
imports: from typing import Union, List, Tuple, Set
  import re
  from spacy.tokens import Doc, Token, Span
  from spacy.util import filter_spans
  from thinc.api import get_array_module
  import catalogue
label_desc: Use image node_id 2 for calling a global function with example usage: split_key(key) and returns: word,  sense