Return the validation split of ImageNet2012.

    Args:
      dl_manager: download manager object.

    Returns:
      validation split.

def _split_generators(self, dl_manager):
    """Return the validation split of ImageNet2012.

    Args:
      dl_manager: download manager object.

    Returns:
      validation split.
    """
    splits = super(Imagenet2012Corrupted, self)._split_generators(dl_manager)
    validation = splits[1]
    return [validation]