title: How to destroy ExtJS application?
body: <p>I am writing unit tests for my ExtJS application.
  I use an authentication method that creates the application upon successful authentication.</p>
  
  <p>But I run into problems if I want to execute this method more than once, since the application would be created more than once.</p>
  
  <p>How can I destroy the ExtJS application?</p>
  
  <p>MyApp.destroy() doesn't work.</p>