title: Junit ExpectedException fail with explanatory message
body: <p>In a junit class, I want to test that an exception is thrown, and if not, provide an explanatory message suggesting what to look for if the test fails. So, something like...</p>
  
  <pre><code>    thrown.expect(UnsupportedOperationException.class);
      thrown.expectMessage("an exception message");
      thrown.failureMessage("This method should not be called directly. Be sure to use a subclass or mock that implements the method foo()");
  </code></pre>
  
  <p>Obviously, there is no such method failureMessage(). I cannot be the only one in the world who has ever wanted to implement a failure message. I have not found an example anywhere in my searches.</p>
  
  <p>Note that this is in reference to the Junit4 @Rule and ExpectedException features.</p>