ApaiIO\Operations\CartAdd::getHMAC PHP Method

    public function getHMAC()
    {
        return $this->getSingleOperationParameter('HMAC');
    }

 public function testGetHMAC()
 {
     $cart = new CartAdd();
     $this->assertEquals(null, $cart->getHMAC());
     $cart->setHMAC('1234');
     $this->assertEquals('1234', $cart->getHMAC());
 }