old_contents: from __future__ import print_function
  from __future__ import unicode_literals
  from __future__ import division
  from __future__ import absolute_import
  from builtins import *  # NOQA
  from future import standard_library
  standard_library.install_aliases()  # NOQA
  
  import chainer
  
  from chainerrl.links.stateless_recurrent import call_recurrent_link
  from chainerrl.links.stateless_recurrent import StatelessRecurrentChainList
  
  
  class StatelessRecurrentBranched(
          StatelessRecurrentChainList, chainer.ChainList):
      """Stateless recurrent parallel link.
  
      This is a recurrent analog to chainerrl.links.Branched. It bundles
      multiple links that implements `StatelessRecurrent`.
  
      Args:
          *links: Child links. Each link should be recurrent and callable.
      """
  
      def n_step_forward(self, sequences, recurrent_state, output_mode):
          if recurrent_state is None:
              n = len(self)
              recurrent_state = [None] * n
          child_ys, rs = tuple(map(tuple, zip(*[
              call_recurrent_link(link, sequences, rs, output_mode)
              for link, rs in zip(self, recurrent_state)])))
          if output_mode == 'concat':
              return child_ys, rs
          assert output_mode == 'split'
          assert len(child_ys) == len(self)
          assert len(child_ys[0]) == len(sequences)
          assert len(rs) == len(self)
          out = list(map(tuple, zip(*child_ys)))
          return out, rs
  
new_contents: from __future__ import print_function
  from __future__ import unicode_literals
  from __future__ import division
  from __future__ import absolute_import
  from builtins import *  # NOQA
  from future import standard_library
  standard_library.install_aliases()  # NOQA
  
  import chainer
  
  from chainerrl.links.stateless_recurrent import call_recurrent_link
  from chainerrl.links.stateless_recurrent import StatelessRecurrentChainList
  
  
  class StatelessRecurrentBranched(
          StatelessRecurrentChainList, chainer.ChainList):
      """Stateless recurrent parallel link.
  
      This is a recurrent analog to chainerrl.links.Branched. It bundles
      multiple links that implements `StatelessRecurrent`.
  
      Args:
          *links: Child links. Each link should be recurrent and callable.
      """
  
      def n_step_forward(self, sequences, recurrent_state, output_mode):
          if recurrent_state is None:
              n = len(self)
              recurrent_state = [None] * n
          child_ys, rs = tuple(zip(*[
              call_recurrent_link(link, sequences, rs, output_mode)
              for link, rs in zip(self, recurrent_state)]))
          if output_mode == 'concat':
              return child_ys, rs
          assert output_mode == 'split'
          assert len(child_ys) == len(self)
          assert len(child_ys[0]) == len(sequences)
          assert len(rs) == len(self)
          out = list(zip(*child_ys))
          return out, rs
  
subject: Simplify code