public void MultiplyLemonsWithCost()
{
//arrange
Store store = new Store();
Lemon lemon = new Lemon();
int lemonsToBuy = 10;
double lemonCost = lemon.GetCost();
double priceOfPurchasedLemons = lemonsToBuy * lemonCost;
double result;
//act
result = store.NumberOfLemonsPurchased(lemonsToBuy);
//assert
Assert.AreEqual(priceOfPurchasedLemons, result);
}