public List <int> SortReturnListOfInts()
        {
            ListOfIntsSixToTen newList = new ListOfIntsSixToTen();

            var sortList = newList.ReturnListOfInts();

            sortList.Sort();

            return(sortList);
        }
        public List <int> ReturnListOfIntsJoin()
        {
            ListOfIntsSixToTen newList            = new ListOfIntsSixToTen();
            List <int>         intsInAnotherClass = newList.ReturnListOfInts();

            List <int> intsInThisClass = new List <int>
            {
                1,
                2,
                3,
                4,
                5
            };

            intsInThisClass.AddRange(intsInAnotherClass);

            return(intsInThisClass);
        }