class_docstr: *CMU ARCTIC* :cite:`Kominek03cmuarctic` dataset.
  
  Args:
      root (str or Path): Path to the directory where the dataset is found or downloaded.
      url (str, optional):
          The URL to download the dataset from or the type of the dataset to download.
          (default: ``"aew"``)
          Allowed type values are ``"aew"``, ``"ahw"``, ``"aup"``, ``"awb"``, ``"axb"``, ``"bdl"``,
          ``"clb"``, ``"eey"``, ``"fem"``, ``"gka"``, ``"jmk"``, ``"ksp"``, ``"ljm"``, ``"lnh"``,
          ``"rms"``, ``"rxr"``, ``"slp"`` or ``"slt"``.
      folder_in_archive (str, optional):
          The top-level directory of the dataset. (default: ``"ARCTIC"``)
      download (bool, optional):
          Whether to download the dataset if it is not found at root path. (default: ``False``).
class_docstr_tok: ["*","CMU","ARCTIC","*",":","cite",":","`","Kominek03cmuarctic","`","dataset",".","Args",":","root","(","str","or","Path",")",":","Path","to","the","directory","where","the","dataset","is","found","or","downloaded",".","url","(","str",",","optional",")",":","The","URL","to","download","the","dataset","from","or","the","type","of","the","dataset","to","download",".","(","default",":","``","``","aew","''","``",")","Allowed","type","values","are","``","``","aew","''","``",",","``","``","ahw","''","``",",","``","``","aup","''","``",",","``","``","awb","''","``",",","``","``","axb","''","``",",","``","``","bdl","''","``",",","``","``","clb","''","``",",","``","``","eey","''","``",",","``","``","fem","''","``",",","``","``","gka","''","``",",","``","``","jmk","''","``",",","``","``","ksp","''","``",",","``","``","ljm","''","``",",","``","``","lnh","''","``",",","``","``","rms","''","``",",","``","``","rxr","''","``",",","``","``","slp","''","``","or","``","``","slt","''","``",".","folder_in_archive","(","str",",","optional",")",":","The","top-level","directory","of","the","dataset",".","(","default",":","``","``","ARCTIC","''","``",")","download","(","bool",",","optional",")",":","Whether","to","download","the","dataset","if","it","is","not","found","at","root","path",".","(","default",":","``","False","``",")","."]
code: def __len__(self) -> int:
      return len(self._walker)
  
file_path: audio/src/torchaudio/datasets/cmuarctic.py
imports: import csv
  import os
  from pathlib import Path
  from typing import Tuple, Union
  import torchaudio
  from torch import Tensor
  from torch.utils.data import Dataset
  from torchaudio._internal import download_url_to_file
  from torchaudio.datasets.utils import _extract_tar
label_desc: Use image node_id 3 for calling the CMUARCTIC obj's underlying member method code with example usage: obj.__len__() and returns: len