public void T11_RemoveAt()
        {
            Pet pet1 = new Pet()
            {
                Age = 10
            };
            Pet pet2 = new Pet()
            {
                Age = 7
            };
            Pet pet3 = new Pet()
            {
                Age = 1
            };
            Pet pet4 = new Pet()
            {
                Age = 8
            };
            Pet pet5 = new Pet()
            {
                Age = 11
            };
            SortableArrayList list = new SortableArrayList();

            list.Add(pet1);
            list.Add(pet2);
            list.Add(pet3);
            list.Add(pet4);
            list.RemoveAt(2);
            Assert.AreEqual(3, list.Count(), "Count should be reduced");

            Assert.AreEqual(pet1, list[0], "pet1 should be on first position");
            Assert.AreEqual(pet2, list[1], "pet2 should be on second position");
            Assert.AreEqual(pet4, list[2], "pet4 should be on third position");

            list.RemoveAt(2);
            Assert.AreEqual(2, list.Count(), "Count should be reduced");
            Assert.AreEqual(pet1, list[0], "pet1 should be on first position");
            Assert.AreEqual(pet2, list[1], "pet2 should be on second position");

            list.RemoveAt(0);
            Assert.AreEqual(1, list.Count(), "Count should be reduced");
            Assert.AreEqual(pet2, list[0], "pet2 should be on first position");

            list.RemoveAt(0);
            Assert.AreEqual(0, list.Count(), "Count should be reduced");

            list.Add(pet4);
            Assert.AreEqual(pet4, list[0], "pet4 should be on first position");
        }