anchor.diff:      };
   
       fadeDelta = mkOption {
  -      type = types.addCheck types.int (x: x > 0);
  +      type = types.ints.positive;
         default = 10;
         example = 5;
         description = ''
  
positive.code:     };
  
      fadeSteps = mkOption {
        type = pairOf (floatBetween "0.01" "1.01");
        default = [ "0.028" "0.03" ];
        example = [ "0.04" "0.04" ];
        description = ''
          Opacity change between fade steps (in and out).
          (numbers in range 0.01 - 1.0)
        '';
      };
  
  
negative.code:     };
  
      activeOpacity = mkOption {
        type = floatBetween 0 1;
        default = 1.0;
        example = 0.8;
        description = ''
          Opacity of active windows.
        '';
      };
  
      inactiveOpacity = mkOption {
        type = floatBetween 0.1 1;
        default = 1.0;
        example = 0.8;
        description = ''
          Opacity of inactive windows.
        '';
      };
  
      menuOpacity = mkOption {
        type = floatBetween 0 1;
        default = 1.0;
        example = 0.8;
        description = ''
          Opacity of dropdown and popup menu.
        '';
      };
  
  