it only access in version 1.2 or latest.

Edit length of "visualMap" array.

Change "map" and "visualMap" fields to "static map" and "static visualMap" fields.
Change "public Board()" constructor to "public static void initialisingBoard()" method.
Change "public void printMap()" method to "static public void printMap()" method.

Change Board's fields and method, to static fields and methods.

calling "setMapByPosition" and "setVisualMapByPosition" methods, commented.
"visualMapMap" and "map" variables add to "setNutsInBoard" method for call by reference in setter method.

The "setMapByPosition" and "setVisualMapByPosition" methods commented and "setVisualMap" , "setMap" and "refresh" methods added.

The "setMapByPosition" and "setVisualMapByPosition" methods commented and "setVisualMap" and "setMap" methods added.