public static string EncodeAll(List <int> numbers)
        {
            var sb = new StringBuilder();

            foreach (var num in numbers)
            {
                Base64VLQ.Encode(sb, num);
            }
            return(sb.ToString());
        }
        public static List <int> DecodeAll(string s)
        {
            var list       = new List <int>();
            var enumerator = s.GetEnumerator();

            while (true)
            {
                var x = Base64VLQ.Decode(enumerator);
                if (x == null)
                {
                    break;
                }
                list.Add(x.Value);
            }
            return(list);
        }