code: def get_funcname(filename: str, lineno: int) -> Optional[str]:
      if filename not in cache:
          _add_file(filename)
      return cache[filename].get(lineno, None)
  
imports: import tokenize
  from typing import Dict, List, Optional
label_desc: Use image node_id 3 for calling a global function with example usage: get_funcname(filename, lineno) and returns: cache