code: def main():
      args = get_args()
      lang_dir = Path(args.lang_dir)
      graph_dir = Path(args.graph_dir)
  
      logging.info(f"Processing {lang_dir} and {graph_dir}")
  
      HLG = compile_HLG(lang_dir, graph_dir, args.ngram_num)
      logging.info(f"Saving HLG.pt to {graph_dir}")
      torch.save(HLG.as_dict(), f"{graph_dir}/HLG.pt")
  
file_path: espnet/egs2/reverb/asr1/pyscripts/k2/compile_hlg.py
imports: import argparse
  import logging
  from pathlib import Path
  import k2
  import torch
  from icefall.lexicon import Lexicon
label_desc: Use image node_id 4 for calling a global function with example usage: main() without return types