title: How to use nose's assert_raises?
body: <p>I've searched for documentation, but couldn't find any. There were a couple that didn't explain much.</p>
  
  <p>Can someone explain to me Nose's </p>
  
  <pre><code>assert_raises(what should I put here?)
  </code></pre>
  
  <p>function and how to use it?</p>