    public function rules() {
        $parentRules = parent::rules();
        $parentRules[] = array(
            'firstName,lastName', 'required', 'on' => 'webForm');
        return $parentRules;
    }
The product receives input or data, but it does
        not validate or incorrectly validates that the input has the
        properties that are required to process the data safely and
        correctly.