<?php
//components
'growl' => [
    'class' => \thread\modules\sys\modules\growl\components\Growl::class,
],

//code
/**
 * @var $growl \thread\modules\sys\modules\growl\components\Growl
 */
$growl = Yii::$app->growl;
$growl->sendToUsersByRole($role, $message, $type = 'notice', $url = '');