public function init()
 {
     parent::init();
     if (!$this->combo instanceof Combo) {
         $this->combo = ArrayHelper::merge(['model' => $this->model, 'attribute' => $this->attribute], $this->combo);
         $this->combo = Yii::createObject($this->combo);
     }
     $this->combo->registerClientConfig();
     $this->pluginOptions = ArrayHelper::merge(['type' => 'combo', 'placement' => 'bottom', 'combo' => $this->combo->getPluginOptions(), 'hash' => $this->combo->configId], $this->pluginOptions);
     $this->registerAssets();
 }