Box constructor
Construct a Box.
Reorders point coordinates as needed to store the upper right and lower left corners, in that order.
https://www.postgresql.org/docs/current/datatype-geometric.html#DATATYPE-GEOMETRIC-BOXES
Implementation
Box(Point p1, Point p2) {
final (x1, x2) = p1.latitude >= p2.latitude
? (p1.latitude, p2.latitude)
: (p2.latitude, p1.latitude);
final (y1, y2) = p1.longitude >= p2.longitude
? (p1.longitude, p2.longitude)
: (p2.longitude, p1.longitude);
_p1 = Point(x1, y1);
_p2 = Point(x2, y2);
}