code: def _is_vowel(char: str) -> bool:
      return (
          char
          in AKKADIAN["short_vowels"]
          + AKKADIAN["macron_vowels"]
          + AKKADIAN["circumflex_vowels"]
      )
  
file_path: cltk/src/cltk/phonology/akk.py
imports: from typing import List, Tuple, Union
label_desc: Use image node_id 3 for calling a global function with example usage: _is_vowel(char) and returns: unknown