public function testEquality()
{
$d1 = new QtiDuration('P1DT12H');
// 1 day + 12 hours.
$d2 = new QtiDuration('P1DT12H');
$d3 = new QtiDuration('PT3600S');
// 3600 seconds.
$this->assertTrue($d1->equals($d2));
$this->assertTrue($d2->equals($d1));
$this->assertFalse($d1->equals($d3));
$this->assertFalse($d3->equals($d1));
$this->assertTrue($d3->equals($d3));
}
