public function testSpeed()
{
$object = new Transition();
$this->assertNull($object->getSpeed());
$this->assertInstanceOf('PhpOffice\\PhpPresentation\\Slide\\Transition', $object->setSpeed());
$this->assertEquals(Transition::SPEED_MEDIUM, $object->getSpeed());
$this->assertInstanceOf('PhpOffice\\PhpPresentation\\Slide\\Transition', $object->setSpeed(Transition::SPEED_FAST));
$this->assertEquals(Transition::SPEED_FAST, $object->getSpeed());
$this->assertInstanceOf('PhpOffice\\PhpPresentation\\Slide\\Transition', $object->setSpeed(rand(1, 1000)));
$this->assertNull($object->getSpeed());
}