Async producer-consumer queue

CommandQueue.cs

async Task Main()
{
	using (var q = new CommandsPipeline(2))
	{
    await Task.Run(()=> {
      var queue = q;
      Parallel.ForEach(string.Format("StringParallelQuery"),
        new ParallelOptions { 
          MaxDegreeOfParallelism = 1
        },
        async (letter) => {
	        await queue.EnqueueTask (() => letter.Dump());
        });
    }).ConfigureAwait(true);	
  }
}

public class CommandsPipeline : IDisposable
{
	BlockingCollection<Action> commandQueue = new BlockingCollection<Action>();
	
	public CommandsPipeline (int parallelDegree)
	{
		// Create and start a separate Task for each consumer:
		for (int i = 0; i < parallelDegree; i++){
			Task.Factory.StartNew (Consume);
    }
	}
	
	public void Dispose() { commandQueue.CompleteAdding(); }
	
	public Task EnqueueTask (Action action) { 
    commandQueue.Add (action); 
    return Task.FromResult(action );
  }
	
	void Consume()
	{
		// This sequence that we’re enumerating will block when no elements
		// are available and will end when CompleteAdding is called.
	
		foreach (Action action in commandQueue.GetConsumingEnumerable()){
			action();     // Perform task.
    }
	}	
}