public function testToString()
{
$time = new Time('20', '30');
$this->assertEquals('20:30:00', $time->toString());
$time = new Time('9', '8', '7');
$this->assertEquals('09:08:07', $time->toString());
$time = new Time(9, 8, 7);
$this->assertEquals('09:08:07', $time->toString());
}