public function testGetReferenceEllipsoid()
{
$datumObject = new Datum();
$datumObject->setDatum(Datum::OSGB36);
$ellipsoid = $datumObject->getReferenceEllipsoid();
// Must return an object...
$this->assertTrue(is_object($ellipsoid));
// ... of the correct type
$this->assertTrue(is_a($ellipsoid, 'Geodetic\\ReferenceEllipsoid'));
}