title: Why is DelegatingSecurityContextRunnable final?
body: <p>I'm using the DelegatingSecurityContextRunnable (in Spring Security 3.2.4), but found it a bit unwieldy. It does not delegate the implementation of toString(). Also, there is no getter for the delegate.</p>
  
  <p>I'm not sure I understand why it's a final class, preventing easy work-arounds/extensions. As it stands now, I have to have my own wrapper around DelegatingSecurityContextRunnable, with extra copies of its fields.</p>
  
  <p>Thoughts?</p>
  
  <p>Jürgen</p>