public void AddRange(ArrayListMimic items)
 {
     foreach (var item in items)
     {
         CheckCount();
         int index = Array.IndexOf(arr, null);
         arr[index] = item;
     }
 }
        //Testing custom Array class acting like ArrayList
        static void MimicTest()
        {
            ArrayListMimic mimic = new ArrayListMimic();

            for (int i = 0; i < 100; i++)
            {
                mimic.Add(1);
            }

            ArrayListMimic test = new ArrayListMimic();

            test.AddRange(mimic);
            int s = test.Capacity();
            //test.Clear();
            bool cnt = test.Contains(2);
            int  t   = test.Count();
        }
 public void CopyTo(ArrayListMimic array, int index)
 {
 }