public void CanApplyStrawberriesSpecialOfferToStrawbsTrolley_ShouldReturn22_50()
{
// arrange
var checkout = new Checkout(_strawbsTrolley);
//act
var discountedTrolley = checkout.ApplyStrawberriesSpecialOffer();
var discountedTotal = checkout.GetTotal();
//assert
Assert.AreNotEqual(discountedTrolley, null);
Assert.AreEqual(discountedTrolley.Count(), 5);
Assert.AreEqual(discountedTotal, 22.50);
}