title: ActionBlock or TransformBlock when just modifying TInput and not creating a different TOutput?
body: <p>When daisy chaining multiple blocks that modify the same <code>TInput</code> elements, I can either use <code>ActionBlock&lt;TInput&gt;</code> or <code>TransformBlock&lt;TInput,TInput&gt;</code>, the difference being that the Transform's delegate would return the same (but modified element) while the Action delegate wouldn't return anything, it would just modify the input element.</p>
  
  <p>Both work, and I suppose both make some sense semantically, but I'm assuming only one of those is the intended way.</p>
  
  <p>If I had to guess, I'd say it's Action because when returning the same elements, it's not really a transformation. But if I had to guess for more pragmatic reasons, I'd say Transform, because if I'm daisy chaining these blocks Transform seems to allow me to post a "processed" element straight to the next block, not sure how I could enforce that with Action.</p>