/**
  * @inheritdoc
  */
 public function bootstrap($app)
 {
     if (!Module::isEnabled()) {
         return true;
     }
     $events = Yii::$app->db->getTableSchema(Item::tableName()) ? (new Item())->moduleEventList() : [];
     EventManagerBootstrap::getEventManager($app)->attachEvents($events);
     return $this;
 }
 public function down()
 {
     return $this->dropTable(Item::tableName());
 }