code: public function expectException($expected = false, $message = '%s')
      {
          $this->expected = $this->forceToExpectation($expected);
          $this->message  = $message;
      }
docs: Sets up an expectation of an exception.
  This has the effect of intercepting an exception that matches.
  
  @param SimpleExpectation $expected    Expected exception to match.
  @param string $message                Message to display.