title: Reading from closed stream
body: <p>I want to test my request builder in unit tests. But I have problem when I want to test my method that makes POST request.I want to test it's content in request stream.
  But the problem is that that I cannot read this stream in my test so I cannot test whether my data is written in right way inside request.
  I have this problem because when I close stream after writing in it in my Request builder class. I cannot open it for reading because after calling the Close() method on stream it becomes unreadable.
  So, is there a way to read a stream after calling Close() method?</p>
  
  <p>If this isn't possible, how would you solve this problem?</p>