title: How to correctly write Parallel.For with async methods
body: <p>How would I structure the code below so that the async method gets invoked?</p>
  
  <pre><code>Parallel.For(0, elevations.Count(), delegate(int i)
  {
     allSheets.AddRange(await BuildSheetsAsync(userID, elevations[i], includeLabels));
  });
  </code></pre>