fix upscalers disappearing after the user reloads UI

        pass

builtin_upscaler_classes = []

forbidden_upscaler_classes = set()

def list_builtin_upscalers():

    builtin_upscaler_classes.clear()

    builtin_upscaler_classes.extend(Upscaler.__subclasses__())

def forbid_loaded_nonbuiltin_upscalers():

    for cls in Upscaler.__subclasses__():

        if cls not in builtin_upscaler_classes:

            forbidden_upscaler_classes.add(cls)

def load_upscalers():

    # We can only do this 'magic' method to dynamically load upscalers if they are referenced,

    # so we'll try to import any _model.py files before looking in __subclasses__

    datas = []

    commandline_options = vars(shared.cmd_opts)

    for cls in Upscaler.__subclasses__():

        if cls in forbidden_upscaler_classes:

            continue

    # some of upscaler classes will not go away after reloading their modules, and we'll end

    # up with two copies of those classes. The newest copy will always be the last in the list,

    # so we go from end to beginning and ignore duplicates

    used_classes = {}

    for cls in reversed(Upscaler.__subclasses__()):

        classname = str(cls)

        if classname not in used_classes:

            used_classes[classname] = cls

    for cls in reversed(used_classes.values()):

        name = cls.__name__

        cmd_name = f"{name.lower().replace('upscaler', '')}_models_path"

        scaler = cls(commandline_options.get(cmd_name, None))

    gfpgan.setup_model(cmd_opts.gfpgan_models_path)

    startup_timer.record("setup gfpgan")

    modelloader.list_builtin_upscalers()

    startup_timer.record("list builtin upscalers")

    modules.scripts.load_scripts()

    startup_timer.record("load scripts")

    modelloader.load_upscalers()

    #startup_timer.record("load upscalers") #Is this necessary? I don't know.

    startup_timer.record("load upscalers") #Is this necessary? I don't know.

    modules.sd_vae.refresh_vae_list()

    startup_timer.record("refresh VAE")

        localization.list_localizations(cmd_opts.localizations_dir)

        modelloader.forbid_loaded_nonbuiltin_upscalers()

        modules.scripts.reload_scripts()

        startup_timer.record("load scripts")