title: Awaiting a non-async method
body: <p>I'm thoroughly confused by the whole await / async pattern in C#.</p>
  
  <p>I have a forms app, and I want to call a method that takes 20 seconds to do a ton of processing. Therefore I want to <code>await</code> it. I thought the correct way was to mark it as <code>async Task</code> but doing this produces a warning because I don't use <code>await</code> anywhere within it.</p>
  
  <p>A google revealed something about returning a <code>TaskCompletionSource&lt;T&gt;</code> but I don't have a return type, since it's void.</p>
  
  <p>How can I call this method using <code>await</code>?</p>