class_docstr: A utility class to help extract subsequences out of a batch
  of sequences
  
  Arguments
  ---------
  word_separator: int
      the index of the word separator (used in p_seq)
  word_separator_base int
      the index of word separators used in unprocessed
      targets (if different)
  
  Example
  -------
  >>> import torch
  >>> from speechbrain.lobes.models.g2p.homograph import SubsequenceExtractor
  >>> extractor = SubsequenceExtractor()
  >>> phns = torch.Tensor(
  ...     [[1, 2, 0, 1, 3, 0, 2, 1, 0],
  ...      [2, 1, 3, 0, 1, 2, 0, 3, 2]]
  ... )
  >>> phn_lens = torch.IntTensor([8, 9])
  >>> subsequence_phn_start = torch.IntTensor([3, 4])
  >>> subsequence_phn_end = torch.IntTensor([5, 7])
  >>> p_seq = torch.Tensor([
  ...     [[0., 1., 0., 0.],
  ...      [0., 0., 1., 0.],
  ...      [1., 0., 0., 0.],
  ...      [0., 1., 0., 0.],
  ...      [0., 0., 0., 1.],
  ...      [1., 0., 0., 0.],
  ...      [0., 0., 1., 0.],
  ...      [0., 1., 0., 0.],
  ...      [1., 0., 0., 0.]],
  ...     [[0., 0., 1., 0.],
  ...      [0., 1., 0., 0.],
  ...      [0., 0., 0., 1.],
  ...      [1., 0., 0., 0.],
  ...      [0., 1., 0., 0.],
  ...      [0., 0., 1., 0.],
  ...      [1., 0., 0., 0.],
  ...      [0., 0., 0., 1.],
  ...      [0., 0., 1., 0.]]
  ... ])
  >>> extractor.extract_seq(
  ...    phns,
  ...    phn_lens,
  ...    p_seq,
  ...    subsequence_phn_start,
  ...    subsequence_phn_end
  ... )
  (tensor([[[0., 1., 0., 0.],
           [0., 0., 0., 1.],
           [0., 0., 0., 0.]],
  <BLANKLINE>
          [[0., 1., 0., 0.],
           [0., 0., 1., 0.],
           [0., 0., 0., 0.]]]), tensor([[1., 3., 0.],
          [1., 2., 0.]]), tensor([0.6667, 1.0000]))
docstr: Pads a subsequence to the length of the longest subsequence
  
  Arguments
  ---------
  sequence: torch.tensor
      the sequence to be padded
  longest_subsequence: int
      the length of the longest subsequence
docstr_tok: ["Pads","a","subsequence","to","the","length","of","the","longest","subsequence","Arguments","--","--","--","--","-","sequence",":","torch.tensor","the","sequence","to","be","padded","longest_subsequence",":","int","the","length","of","the","longest","subsequence"]
code: def _pad_subsequence(self, sequence, longest_subsequence):
      """Pads a subsequence to the length of the longest subsequence
  
      Arguments
      ---------
      sequence: torch.tensor
          the sequence to be padded
      longest_subsequence: int
          the length of the longest subsequence
      """
      if longest_subsequence > 0:
          sequence = torch.nn.functional.pad(
              sequence, (0, longest_subsequence)
          )
      return sequence
  
imports: import torch
  from torch import nn
label_desc: Use image node_id 4 for calling the SubsequenceExtractor obj's underlying member method code with example usage: obj._pad_subsequence(sequence, longest_subsequence) and returns: sequence