public void AddTextToList_AddNumberTextToList_List()
        {
            TextNumber newTextNumber = new TextNumber();

            newTextNumber.SetNumber("15");
            newTextNumber.AddTextToList();
            List <string> result  = newTextNumber.GetTextList();
            List <string> newList = new List <string>()
            {
                "five"
            };

            CollectionAssert.AreEqual(newList, result);
        }