code: def dump(props, fp, separator='=', comments=None, timestamp=True,
           sort_keys=False):
      if comments is not None:
          print(to_comment(comments), file=fp)
      if timestamp is not None and timestamp is not False:
          print(to_comment(java_timestamp(timestamp)), file=fp)
      for k,v in itemize(props, sort_keys=sort_keys):
          print(join_key_value(k, v, separator), file=fp)