private void RunStandaloneThreads(int count, ThreadAction action)
        {

            //z lambdy ma dostep do _data oraz do zmiennej sum i wykonuje to kazdy watek
            // TODO: Run 'count' threads and execute 'action' in every one with appropriate range of data

            List<Thread> threads = new List<Thread>();
            var move = _data.Length / count;
            var a = 0;

            for (var i = 0; i < count; i++)
            {
                var start = a;
                var stop = a + move;
                a += move;
                if (i == count - 1)
                {
                    stop = _data.Length;
                }

                var unused = new Thread(() => action(start, stop));
                unused.Start();
                threads.Add(unused);
            }

            foreach (var thread in threads)
                thread.Join();


        }