TPL DataFlow Run Multiple At Once

   async Task ProcessMultipleAtOnce<T>(int maxDegreeOfParallelism, IEnumerable<T> items, Func<T, Task> func)
        {
            var actionBlock = new ActionBlock<T>(func, new ExecutionDataflowBlockOptions { MaxDegreeOfParallelism = maxDegreeOfParallelism });

            foreach (T item in items)
            {
                await actionBlock.SendAsync(item);
            }

            actionBlock.Complete();

            await actionBlock.Completion;
        }
// https://stackoverflow.com/a/14076323/1987788