code: def save(sentences, file):
      n = len(sentences)
      content = "\n\n".join(sentences) + "\n"
      print(f"Save {n} sentences in {file}")
      with open(file, "w") as f:
          f.write(content)
  
imports: import os
  import shutil
  from os.path import join
  from underthesea.file_utils import DATASETS_FOLDER
label_desc: Use image node_id 2 for calling the CONLLReader obj's underlying member method code with example usage: obj.save(sentences, file) without return types