public void TestWhenNoRepeatableNumbers()
        {
            List<int> sequence = new List<int>() {
                1, 2, 6, 7, 8, 1, 2, 4, 5 };
            SequenceOperationsEngine engine = new SequenceOperationsEngine();

            List<int> subsequence = engine.FindSubsequence(sequence);
            List<int> expected = new List<int>() { };

            CollectionAssert.AreEqual(expected, subsequence);
        }
        public void TestIfLongestAtTheEnd()
        {
            List<int> sequence = new List<int>() {
                1, 1, 2, 2, 6, 7, 8, 1, 2, 4, 4, 5, 5, 5, 5, 5 };
            SequenceOperationsEngine engine = new SequenceOperationsEngine();

            List<int> subsequence = engine.FindSubsequence(sequence);
            List<int> expected = new List<int>() { 5, 5, 5, 5, 5 };

            CollectionAssert.AreEqual(expected, subsequence);
        }
    static void Main()
    {
        SequenceOperationsEngine engine = new SequenceOperationsEngine();
        List<int> sequence = new List<int>() { 4, 5, 1, 2, 2, 2, 1, 3, 5, 1, 5 };

        List<int> subsequence = engine.FindSubsequence(sequence);

        if (subsequence.Count > 0)
        {
            Console.WriteLine(engine.SequenceToString(subsequence));
        }
        else
        {
            Console.WriteLine("There is no such subsequence bigger than 1 element.");
        }
    }