public class DroidStatus
{
    public static final int COLLISION = 0;
    public static final int MOVED = 1;
    public static final int ARRIVED = 2;
    public static final int BACKUP = 3;

    public static final String toString (int status)
    {
        switch (status)
        {
            case COLLISION:
                return "COLLISION";
            case MOVED:
                return "MOVED";
            case ARRIVED:
                return "ARRIVED";
            case BACKUP:
                return "BACKUP";
            default:
                return "UNKNOWN";
        }
    }

    private DroidStatus ()  // prevent instantiation
    {
    }
}
@@ -175,18 +175,59 @@
 int 
-BACKUP = 3
+VISITED = 3;%0A    public static final int ERROR = 10
 ;%0A%0A 
@@ -515,22 +515,23 @@
    case 
-BACKUP
+VISITED
 :%0A      
@@ -552,14 +552,15 @@
 rn %22
-BACKUP
+VISITED
 %22;%0A 
@@ -607,15 +607,13 @@
 rn %22
-UNKNOWN
+ERROR
 %22;%0A 

Update DroidStatus.java