      """
      def __init__(self,
                   parent: tk.Frame,
                   scale_var: tk.StringVar,
                   screen_dimensions: Tuple[int, int]) -> None:
          logger.debug("Initializing %s (parent: '%s', scale_var: %s, screen_dimensions: %s)",
                       self.__class__.__name__, parent, scale_var, screen_dimensions)
          frame = tk.Frame(parent)
          super().__init__(frame)
  
 
</s> remove     def __init__(self, parent: tk.Frame, is_standalone: bool) -> None:
        logger.debug("Initializing %s (parent: '%s', is_standalone: %s)",
                     self.__class__.__name__, parent, is_standalone)
        super().__init__(parent)
 </s> add     def __init__(self, parent: tk.Frame, taskbar: Optional[ttk.Frame]) -> None:
        logger.debug("Initializing %s (parent: '%s', taskbar: %s)",
                     self.__class__.__name__, parent, taskbar)
        self._is_standalone = taskbar is None
        self._gui_mapped: List[tk.Widget] = []
        self._frame = tk.Frame(parent) if taskbar is None else taskbar
 </s> remove     is_standalone: bool
        ``True`` if preview is a pop-up window otherwise ``False``
 </s> add     taskbar: :class:`tkinter.ttk.Frame` or ``None``
        None if preview is a pop-up window otherwise ttk.Frame if taskbar is managed by the GUI </s> remove         self.update_preview = get_config().tk_vars.update_preview
 </s> add         logger.debug("Initializing %s (args: %s, kwargs: %s)",
                     self.__class__.__name__, args, kwargs)
        self._preview = get_images().preview_train
        self._display: Optional[PreviewTk] = None </s> remove     def __init__(self, save_variable: tk.BooleanVar) -> None:
        logger.debug("Initializing %s: (save_variable: %s)",
                     self.__class__.__name__, save_variable)
 </s> add     def __init__(self, save_variable: tk.BooleanVar, is_standalone: bool) -> None:
        logger.debug("Initializing %s: (save_variable: %s, is_standalone: %s)",
                     self.__class__.__name__, save_variable, is_standalone)
        self._is_standalone = is_standalone
                 screen_dimensions: Tuple[int, int],
                 is_standalone: bool) -> None:
      """
      def __init__(self,
                   parent: tk.Frame,
                   scale_var: tk.StringVar,
                 screen_dimensions: Tuple[int, int],
                 is_standalone: bool) -> None:
          logger.debug("Initializing %s (parent: '%s', scale_var: %s, screen_dimensions: %s)",
                       self.__class__.__name__, parent, scale_var, screen_dimensions)
          frame = tk.Frame(parent)
          super().__init__(frame)
  
keep keep keep keep replace keep keep keep keep keep
 GUI - Preview updates
  - Training preview. Embed preview pop-out window
  - Bugfix - convert/extract previews 
lib/training/preview_tk.py