class_docstr: TokenSpan()
  Token with time stamps and score. Returned by :py:func:`merge_tokens`.
docstr: Returns the time span
code: def __len__(self) -> int:
      """Returns the time span"""
      return self.end - self.start
  
file_path: audio/src/torchaudio/functional/_alignment.py
imports: from dataclasses import dataclass
  from typing import List, Optional, Tuple
  import torch
  from torch import Tensor
  from torchaudio._extension import fail_if_no_align
label_desc: Use image node_id 1 for calling the TokenSpan obj's underlying member method code with example usage: obj.__len__() and returns: unknown