public function apply(PHPUnit_Util_Metrics $metrics)
 {
     $parameters = $metrics->getParameters();
     if ($parameters >= $this->threshold) {
         return sprintf("Function or method has %d parameters.\n" . 'Long parameter lists can indicate that a new object should be ' . 'created to wrap the numerous parameters. Basically, try to ' . 'group the parameters together.', $parameters);
     }
 }