public void Tail_ist_leer_wenn_liste_1_element_hat()
        {
            var getTail = new GetTail();
            var tail    = getTail.Execute(new[] { 3 });

            Assert.AreEqual(tail.Length, 0);
        }
        public void Tail_der_Liste_korrekt_erhalten()
        {
            var getTail = new GetTail();
            var tail    = getTail.Execute(new[] { 3, 4, 5, });

            Assert.AreEqual(tail.Length, 2);
            Assert.AreEqual(tail[0], 4);
            Assert.AreEqual(tail[1], 5);
        }