title: HttpClient complains about concurrent IO read and write operations
body: <p>I have an F# funciton that uses a static instance of HttpClient:</p>
  
  <pre><code>let executeRequest request =
      async {
          let! response = StaticHttpClient.Instance.SendAsync(request) |&gt; Async.AwaitTask
          let! stream = response.Content.ReadAsStreamAsync() |&gt; Async.AwaitTask
          return (stream, response.StatusCode)
      }
      |&gt; Async.RunSynchronously
  </code></pre>
  
  <p>When the request body is large, the function often throws an AggregateException with inner exception "NotSupportedException: The stream does not support concurrent IO read or write operations."</p>
  
  <p>I wonder why this happens. Looks like there is an attempt to use response stream before the request is stream is fully processed. But why?</p>