}
public static EastNorth sum(EastNorth en1, EastNorth en2) {
return new EastNorth(en1.east() + en2.east(), en1.north() + en2.north());
}
public static EastNorth diff(EastNorth en1, EastNorth en2) {
return new EastNorth(en1.east() - en2.east(), en1.north() - en2.north());
}