          self._busy_tkvar = tk_vars["busy"]
          self._tk_vars = dict()
  
          d_locals = locals()
          defaults = {opt: self._format_to_display(d_locals["selected_{}".format(opt)])
                      for opt in self._options}
          self._busy_indicator = self._build_frame(defaults,
                                                   refresh_callback,
                                                   patch_callback,
                                                   available_masks,
 
</s> remove         self._tk_vars = dict()
 </s> add         self._tk_vars = {} </s> remove         self._faces = dict()
 </s> add         self._faces = {} </s> remove         self._faces = dict()
 </s> add         self._faces = {} </s> remove         self._tabs = dict()
 </s> add         self._tabs = {} </s> remove                 text = _("Save {} config").format(title)
 </s> add                 text = _(f"Save {title} config")
        defaults = {opt: self._format_to_display(d_locals[f"selected_{opt}"])
          self._busy_tkvar = tk_vars["busy"]
          self._tk_vars = dict()
  
          d_locals = locals()
        defaults = {opt: self._format_to_display(d_locals[f"selected_{opt}"])
                      for opt in self._options}
          self._busy_indicator = self._build_frame(defaults,
                                                   refresh_callback,
                                                   patch_callback,
                                                   available_masks,
keep keep keep keep replace keep keep keep keep keep
 bugfix: Preview Tool, ensure all config items are written 
tools/preview/preview.py