public class DroidMovement
{
    public static final int NORTH = 1;
    public static final int SOUTH = 2;
    public static final int WEST = 3;
    public static final int EAST = 4;

    public static final String toString (int direction)
    {
        switch (direction)
        {
            case NORTH:
                return "NORTH";
            case SOUTH:
                return "SOUTH";
            case WEST:
                return "WEST";
            case EAST:
                return "EAST";
            default:
                return "UNKNOWN";
        }
    }

    public static final String toString (String direction)
    {
        switch (direction)
        {
            case "1":
                return "NORTH";
            case "2":
                return "SOUTH";
            case "3":
                return "WEST";
            case "4":
                return "EAST";
            default:
                return "UNKNOWN";
        }
    }

    private DroidMovement ()  // prevent instantiation
    {
    }
}
@@ -177,16 +177,492 @@
 T = 4;%0A%0A
+    public static final int backup (int direction)%0A    %7B%0A        switch (direction)%0A        %7B%0A            case NORTH:%0A                return SOUTH;%0A            case SOUTH:%0A                return NORTH;%0A            case WEST:%0A                return EAST;%0A            case EAST:%0A                return WEST;%0A            default:%0A            %7B%0A                System.out.println(%22Error - invalid direction: %22+direction);%0A%0A                return 0;%0A            %7D%0A        %7D%0A    %7D%0A%0A
     publ

Update DroidMovement.java