Example: $point = new GeoPoint(37.423147, -122.085015);
See also: https://cloud.google.com/datastore/reference/rest/Shared.Types/LatLng LatLng
 /**
  * @expectedException InvalidArgumentException
  */
 public function testInvalidTypeLongitude()
 {
     $point = new GeoPoint(1.1, 2.2);
     $point->setLongitude('bar');
 }