title: Argument 2 passed to PHPUnit_Framework_ExpectationFailedException::__construct() must be an instance of PHPUnit_Framework_ComparisonFailure
body: <p>I get this error when I run phpunit with selenium.</p>
  
  <p>When I check the class <code>PHPUnit_Framework_ExpectationFailedException</code>, I found the following line :</p>
  
  <pre><code>public function __construct($message, PHPUnit_Framework_ComparisonFailure $comparisonFailure = NULL)
  </code></pre>
  
  <p>Indeed, the second parameter has to be an object and not a string but if I check the class <code>SeleniumTestCase</code>, I can see :</p>
  
  <pre><code>    if ($e instanceof PHPUnit_Framework_ExpectationFailedException) {
          if (is_object($e-&gt;getComparisonFailure())) {
              $message = $e-&gt;getComparisonFailure()-&gt;toString();
          } else {
              $message = $e-&gt;getMessage();
          }
  
          $buffer .= "\n" . $message;
  
          throw new PHPUnit_Framework_ExpectationFailedException($buffer, $message);
  </code></pre>
  
  <p>The <code>$message</code> seems to be a string and not an object.</p>
  
  <p>Can you help me ?</p>
  
  <p><strong>PS:</strong> I am using the version of phpunit (3.6.4) and the last version of selenium (1.1.1)</p>