function testDiscount()
{
$this->setUp();
$cart = new EShoppingCart();
$cart->discounts = array(array('class' => 'ext.yiiext.components.shoppingCart.discounts.TestDiscount', 'rate' => 40));
$book = Book::model()->findByPk(1);
$cart->put($book, 2);
$this->assertEquals(159.84, $cart->getCost());
}