code: def generate(self, state_size=None, start=(), dataset='', backward=False):
          
          if state_size is None:
              try:
                  state_size = next(iter(self.parser.state_sizes))
              except StopIteration:
                  return
          #elif (self.parser is not None
          #      and state_size not in self.parser.state_sizes):
          #    raise ValueError('invalid state size: {0}: not in {1}'
          #                     .format(state_size, self.parser.state_sizes))
          dataset += state_size_dataset(state_size)
          return self.storage.generate(start, state_size, dataset, backward)
docs: Generate a sequence.
  
          Parameters
          ----------
          state_size : `int`, optional
              State size (default: parser.state_sizes[0]).
          start : `str` or `iterable` of `str`, optional
              Initial state (default: ()).
          dataset : `str`, optional
              Dataset key prefix.
          backward : `bool`, optional
              Link direction.
  
          Returns
          -------
          `generator` of `str`
              State generator.