title: Re-enable asserts in Python optimized mode
body: <p>I have some functions with asserts. Now when I run the optimized mode, asserts don't fire anymore.</p>
  <p>Now I need to reenable asserts in one function, despite optimization.</p>
  <pre><code>@reenable_asserts
  def some_fn():
      assert xyz # this should be executed even with -O flag
  </code></pre>
  <p>Is that possible?</p>