anchor.diff:        example = "0.8";
         description = ''
           Opacity of dropdown and popup menu (number in range 0.0 - 1.0).
  +      '';
  +    };
  +
  +    wintypes = mkOption {
  +      type = types.attrs;
  +      default = { popup_menu = { opacity = cfg.menuOpacity; }; dropdown_menu = { opacity = cfg.menuOpacity; }; };
  +      example = {};
  +      description = ''
  +        Rules for specific window types.
         '';
       };
   
  
positive.code:       example = [
          "window_type *= 'menu'"
          "name ~= 'Firefox$'"
          "focused = 1" 
        ];
        description = ''
          List of conditions of windows that should not be faded.
  
negative.code:       example = [
          "window_type *= 'menu'"
          "name ~= 'Firefox$'"
          "focused = 1"
        ];
        description = ''
          List of conditions of windows that should have no shadow.
  