public static int LastIndexOf<T>(this IReadOnlyList<T> s, IReadOnlyList<T> t, int startIndex, 
            IEqualityComparer<T> comparer) where T : IEquatable<T>
        {
            Validate(s, t, startIndex);

            // Follow the behavior of string.LastIndexOf(string) method. 
            if (t.Count == 0) return 0;
            if (s.Count == 0 || s.Count < t.Count) return -1;

            if (comparer == null) comparer = EqualityComparer<T>.Default;
            if (t.Count == 1) return LastIndexOf(s, t[0], startIndex, comparer);

            var table = BuildTable(t, comparer);
            var i = 0;  

            while (startIndex - i >= 0)  
            {
                if (comparer.Equals(t[t.Count - i - 1], s[startIndex - i]))
                {
                    if (i == t.Count - 1)
                        return startIndex - t.Count + 1;
                    i++;
                }
                else
                {
                    if (table[i] > -1)
                    {
                        startIndex -= i;
                        i = table[i];
                    }
                    else
                    {
                        startIndex--;
                        i = 0;
                    }
                }
            }
            return -1;
        }