public void should_caculate_ZT_postage_for_Food_More_Than_5KG()
 {
     var food = new Food(7);
     var postage = new PostageCalculator().GetPostage(new List<IPostable> { food }, m_Zt);
     Assert.AreEqual(18, postage);
 }
 public void should_caculate_SF_postage_for_food()
 {
     var food = new Food(4);
     var postage = new PostageCalculator().GetPostage(new List<IPostable> { food }, m_Sf);
     Assert.AreEqual(16, postage);
 }