private function assertPeriod(Period $test, $y, $m, $d)
{
$this->assertEquals($test->getYears(), $y, "years");
$this->assertEquals($test->getMonths(), $m, "months");
$this->assertEquals($test->getDays(), $d, "days");
$this->assertEquals($test->toTotalMonths(), $y * 12 + $m, "totalMonths");
}