code: def pad_and_reverse(rnn_output, seq_lengths):
      rnn_output, _ = nn.utils.rnn.pad_packed_sequence(
          rnn_output, batch_first=True
      )
      reversed_output = reverse_sequences(rnn_output, seq_lengths)
      return reversed_output
  
file_path: pyro/pyro/contrib/examples/polyphonic_data_loader.py
imports: import os
  import pickle
  from collections import namedtuple
  from urllib.request import urlopen
  import torch
  import torch.nn
  from torch.nn.utils.rnn import pad_sequence
  from pyro.contrib.examples.util import get_data_directory
label_desc: Use image node_id 4 for calling a global function with example usage: pad_and_reverse(rnn_output, seq_lengths) and returns: reversed_output