code: def dumps(graphs, triples=False, cls=PENMANCodec, **kwargs):
      
      codec = cls(**kwargs)
      strings = [codec.encode(g, triples=triples) for g in graphs]
      return '\n\n'.join(strings)
docs: Serialize each graph in *graphs* to the PENMAN format.
  
      Args:
          graphs: an iterable of Graph objects
          triples: if True, write graphs as triples instead of as PENMAN
      Returns:
          the string of serialized graphs