code: def find_classes(folder:Path)->FilePathList:
      "List of label subdirectories in imagenet-style `folder`."
      classes = [d for d in folder.iterdir()
                 if d.is_dir() and not d.name.startswith('.')]
      assert(len(classes)>0)
      return sorted(classes, key=lambda d: d.namef find_classes(folder:Path)->FilePathList:
      "List of label subdirectories in imagenet-style `folder`."
      classes = [d for d in folder.iterdir()
                 if d.is_dir() and not d.name.startswith('.')]
      assert(len(classes)>0)
      return sorted(classes, key=lambda d: d.name)
docs: List of label subdirectories in imagenet-style `folder`.