private boolean corner(int i){
        int[][] corners = {
                {0,0},
                {0,2},
                {2,0},
                {2,2},
        };

        if(i<corners.length){
            if(isEmpty(corners[i][0],corners[i][1])){
                x = corners[i][0];
                y = corners[i][1];
                return true;
            }
            else
            {
                return corner(++i);
            }
        }
        else{
            return false;
        }
    }