code: def convert_sent_dict_to_conll(sent_dic, domain) -> str:
      
      return '\n\n'.join(['\n'.join(['\t'.join(map(str, pad_line_to_ontonotes(line, domain)))
                                     for line in convert_sent_to_conll(sent_ls)])
                          for sent_ls
                          in sent_dic.iteritems()])
docs: Given a dictionary from sentence -> extractions,
      return a corresponding CoNLL representation.