lsun.py can't load classes list

[ryhhtn]

thank you for this code.

I tried to load several lsun dataset. but _verify_classes is error

Replacement index 1 out of range for positional args tuple
  File "/home/vscode/ddim/datasets/lsun.py", line 112, in _verify_classes
    verify_str_arg(classes, "classes", dset_opts)

""" LSUN <https://www.yf.io/p/lsun>_ dataset.

Args: root (string): Root directory for the database files. classes (string or list): One of {'train', 'val', 'test'} or a list of categories to load. e,g. ['bedroom_train', 'church_outdoor_train']. transform (callable, optional): A function/transform that takes in an PIL image and returns a transformed version. E.g, transforms.RandomCrop target_transform (callable, optional): A function/transform that takes in the target and transforms it. """

this code is bug or mistake usage