code: def _main(filenames: list[str] | None = None) -> None:
      filenames = filenames or sys.argv[1:]
      for filename in filenames:
          with open(filename) as f:
              cpp = Monitor(filename, verbose=True)
              print()
              print(filename)
              for line in f:
                  cpp.writeline(line)
  
file_path: cpython/Tools/clinic/libclinic/cpp.py
imports: import dataclasses
  import re
  import sys
  from typing import NoReturn
  from .errors import ParseError
label_desc: Use image node_id 2 for calling a global function with example usage: _main(filenames) without return types