title: Are there any conventions on throwing exceptions from implementations of IObserver?
body: <p>I'm implementing IObserver.</p>
  
  <p>Are there any conventions about throwing exceptions from IObserver?</p>
  
  <p>Can OnNext or any other method of my implementation throw exceptions?</p>
  
  <p>What should happen if exception is thrown in OnNext or OnCompleted - should I catch all exceptions and call this.OnError(ex)?</p>
  
  <p>What will happen if OnError throws?</p>