Linking blocks to create a pipeline

var httpClient = new HttpClient();

// Create a block the accepts a uri and returns its contents as a string
var downloaderBlock = new TransformBlock<string, string>(
    async uri => await httpClient.GetStringAsync(uri));

// Create a block that accepts the content and prints it to the console
var printerBlock = new ActionBlock<string>(
    contents => Console.WriteLine(contents));

// Make the downloaderBlock complete the printerBlock when its completed.
var dataflowLinkOptions = new DataflowLinkOptions {PropagateCompletion = true};

// Link the block to create a pipeline
downloaderBlock.LinkTo(printerBlock, dataflowLinkOptions);

// Post urls to the first block which will pass their contents to the second one.
downloaderBlock.Post("http://youtube.com");
downloaderBlock.Post("http://github.com");
downloaderBlock.Post("http://twitter.com");

downloaderBlock.Complete(); // Completion will propagate to printerBlock
await printerBlock.Completion; // Only need to wait for the last block in the pipeline