public double sphericalDistance(LatLong other) {
        return LatLongUtils.sphericalDistance(this, other);
    }
@Test
    public void sphericalDistance_nearOfSriLankaToIslaGenovesa_returnHalfOfEarthEquatorCircumference() {
        // These coordinates are 1/4 Earth circumference from zero on the equator
        LatLong nearSriLanka = new LatLong(0d, 90d);
        // These coordinates are 1/4 Earth circumference from zero on the equator
        LatLong islaGenovesa = new LatLong(0d, -90d);

        // These points are as far apart as they could be, half way around the earth
        double spherical = LatLongUtils.sphericalDistance(nearSriLanka, islaGenovesa);
        assertEquals(EARTH_EQUATOR_CIRCUMFERENCE / 2, spherical, 0d);
    }