private function getAnnotation(Reflector $element, $annotation)
    {
        if ($element instanceof ReflectionClass) {
            return $this->reader->getClassAnnotation($element, $annotation);
        } elseif ($element instanceof ReflectionMethod) {
            return $this->reader->getMethodAnnotation($element, $annotation);
        } elseif ($element instanceof ReflectionProperty) {
            return $this->reader->getPropertyAnnotation($element, $annotation);
        }

        return null;
    }