public void AddItemToList_NoError()
 {
     try
     {
         ItemAccessor.AddItemToList("Gumballs", 20, 1);
     }
     catch (InvalidOperationException e)
     {
         StringAssert.Contains(e.Message, "");
     }
     return;
 }
 public void AddItemToList_InvalidQty()
 {
     try
     {
         ItemAccessor.AddItemToList("Dog Food", -23, 2);
     }
     catch (InvalidOperationException e)
     {
         StringAssert.Contains(e.Message, "");
         return;
     }
     Assert.Fail("The expected exception was not thrown.");
 }