public class TileId
{
    public static final char BUG = '#';
    public static final char EMPTY_SPACE = '.';

    private TileId ()
    {
    }
}
@@ -104,16 +104,192 @@
 = '.';%0A%0A
+    public static boolean valid (char check)%0A    %7B%0A        if ((check == BUG) %7C%7C (check == EMPTY_SPACE))%0A            return true;%0A        else%0A            return false;%0A    %7D%0A%0A
     priv

Update TileId.java