public function testGetDiscountAmount()
{
$item = new Item();
$item->setUnitaryCost(80);
$item->setQuantity(1);
$this->assertEquals(0, $item->getDiscountAmount());
$item->setDiscount(10);
$this->assertEquals(8, $item->getDiscountAmount());
$item->setDiscount(2);
$this->assertEquals(1.6, $item->getDiscountAmount());
}
