title: Is HttpClient safe to use concurrently?
body: <p>In all the examples I can find of usages of <code>HttpClient</code>, it is used for one off calls. But what if I have a persistent client situation, where several requests can be made concurrently? Basically, is it safe to call <code>client.PostAsync</code> on 2 threads at once against the same instance of <code>HttpClient</code>.</p>
  
  <p>I am not really looking for experimental results here. As a working example could simply be a fluke (and a persistent one at that), and a failing example can be a misconfiguration issue. Ideally I'm looking for some authoritative answer to the question of concurrency handling in HttpClient.</p>