code: def get_answer(solution: Optional[str]) -> Optional[str]:
      if solution is None:
          return None
      last_boxed = last_boxed_only_string(solution)
      if last_boxed is None:
          return None
      answer = remove_boxed(last_boxed)
      if answer is None:
          return None
      return answer
  
file_path: autogen/autogen/math_utils.py
imports: from typing import Optional
  from autogen import oai, DEFAULT_MODEL
label_desc: Use image node_id 9 for calling a global function with example usage: get_answer(solution) and returns: answer, None, None, None