docs: def save_csv(data,  # type: Iterable[Tuple[Union[str, int], ...]]
               headers,  # type: Iterable[str]
               file  # type: TextIO
               ):
      # type: (...) -> None
      """
      Output generated data to file as CSV with header.
  
      :param data: An iterable of tuples containing raw data.
      :param headers: Iterable of feature names
      :param file: A writeable stream in which to write the CSV
      """
  
      print(','.join(headers), file=file)
      writer = csv.writer(file)
      writer.writerows(data)