title: what exception can I use for general network problems?
body: <p>In my case server is not available and so I can not read data for client and so I want to throw an Exception.
  What Exception should I throw?
  I don't want to create my own exception class for such situation, because there are a lot of different situations in program.</p>
  
  <p>Probably there are some kind of "general" exception, like "NetworkProblem" or even just "Problem" or something?</p>
  
  <p>I don't need anything specific, just an exception with message.</p>