code: def reset_backward_rnn_state(
      states: Union[torch.Tensor, List[Optional[torch.Tensor]]]
  ) -> Union[torch.Tensor, List[Optional[torch.Tensor]]]:
      """Set backward BRNN states to zeroes.
  
      Args:
          states: Encoder hidden states.
  
      Returns:
          states: Encoder hidden states with backward set to zero.
  
      """
      if isinstance(states, list):
          for state in states:
              state[1::2] = 0.0
      else:
          states[1::2] = 0.0
  
      return states
  
imports: from argparse import Namespace
  from typing import List, Optional, Tuple, Union
  import numpy
  import torch
  import torch.nn.functional
  from torch.nn.utils.rnn import pack_padded_sequence, pad_packed_sequence
  from espnet.nets.e2e_asr_common import get_vgg2l_odim
  from espnet.nets.pytorch_backend.nets_utils import make_pad_mask, to_device
label_desc: Use image node_id 1 for calling a global function with example usage: reset_backward_rnn_state(states) and returns: states