code: protected function describeDifference($expected, $parameters)
      {
          if (count($expected) != count($parameters)) {
              return sprintf(
                  'Expected %s arguments of [%s], but got %s arguments of [%s]',
                      count($expected),
                      $this->renderArguments($expected),
                      count($parameters),
                      $this->renderArguments($parameters)
              );
          }
          $messages = array();
          for ($i = 0; $i < count($expected); $i++) {
              $comparison = $this->forceToExpectation($expected[$i]);
              if (! $comparison->test($parameters[$i])) {
                  $messages[] = 'parameter ' . ($i + 1) . ' with [' .
                          $comparison->overlayMessage($parameters[$i], $this->getDumper()) . ']';
              }
          }
  
          return 'Parameter expectation differs at ' . implode(' and ', $messages);
      }
docs: Message to display if expectation differs from the parameters actually received.
  
  @param array $expected      Expected parameters as list.
  @param array $parameters    Actual parameters received.
  
  @return string              Description of difference.