/// <summary>
        /// Удаление по значению
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public bool Remove(T data)
        {
            var current = firstElement;
            ListElements <T> previous = null;

            while (current != null)
            {
                if (current.Data.Equals(data))
                {
                    if (previous != null)
                    {
                        previous.Next = current.Next;
                        if (current.Next == null)
                        {
                            lastElement = previous;
                        }
                    }
                    else
                    {
                        firstElement = firstElement.Next;

                        if (firstElement == null)
                        {
                            lastElement = null;
                        }
                    }

                    count--;
                    return(true);
                }
                previous = current;
                current  = current.Next;
            }
            return(false);
        }
        /// <summary>
        /// Вставка по индексу
        /// </summary>
        /// <param name="index"></param>
        /// <param name="data"></param>
        public void InsertOf(int index, T data)
        {
            var newListElement        = new ListElements <T>(data);
            var current               = firstElement;
            ListElements <T> previous = null;

            while (index > 0 && current != null)
            {
                previous = current;
                current  = current.Next;
                index--;
            }
            if (current != null)
            {
                newListElement.Data = data;
                newListElement.Next = current;
                if (previous == null)
                {
                    firstElement = newListElement;
                }
                else
                {
                    previous.Next = newListElement;
                }
            }
            count++;
        }
        /// <summary>
        /// Добавление в конец списка
        /// </summary>
        /// <param name="data"></param>
        public void Add(T data)
        {
            var newListElement = new ListElements <T>(data);

            if (firstElement == null)
            {
                firstElement = newListElement;
            }
            else
            {
                lastElement.Next = newListElement;
            }

            lastElement = newListElement;
            count++;
        }