title: Android Unit Testing: How to wait for Activity to update UI
body: <p>I'm trying to test my UI within an Activity. 
  However, this Activity performs some background network operations and on the response updates it's fragments to the actual component that I'm trying to test.</p>
  
  <p>My unit test is failing because it is trying to assertNotNull on the views that have been rendered to the screen yet.</p>
  
  <p>How would I go about signaling to my unit test that the Activity has performed this background operation and everything should be ready for setUp and testing?</p>