func (r *RectBounder) maxErrorForTests() LatLng {
	return LatLng{10 * dblEpsilon * s1.Radian, 1 * dblEpsilon * s1.Radian}
}
maxErrorForTests returns the maximum error in RectBound provided that the
result does not include either pole. It is only used for testing purposes
package s2
import (
	"math"
	"github.com/golang/geo/r1"
	"github.com/golang/geo/r3"
	"github.com/golang/geo/s1"
)
type RectBounder struct {
	a Point
	aLL   LatLng
	bound Rect
}
func NewRectBounder() *RectBounder {
	return &RectBounder{
		bound: EmptyRect(),
	}
}