private bool CheckIndexAndValue(int index, int value)
        {
            if (index == 0 && value < this[index + 1])
            {
                return true;
            }

            else if (value > this[index - 1] &&
                (index == Count || value < this[index + 1]))
            {
                return true;
            }

            else if (value > this[index - 1] &&
                (index == Count || value < this[index]))
            {
                return true;
            }

            return false;
        }