code: def download_urls(self):
      
      urls = {
          tfds.Split.TRAIN: ["train_clean100"],
          tfds.Split.VALIDATION: ["dev_clean"],
          tfds.Split.TEST: ["test_clean"],
      }
      if self.data in ["all", "clean360"]:
        urls[tfds.Split.TRAIN].append("train_clean360")
      if self.data == "all":
        urls[tfds.Split.TRAIN].extend(["train_clean360", "train_other500"])
        urls[tfds.Split.VALIDATION].append("dev_other")
        urls[tfds.Split.TEST].append("test_other")
  
      urls = {
          split: [_DL_URLS[name] for name in names
                 ] for split, names in urls.items()
      }
      return urls
docs: Returns download urls for this config.