src/widget/Multiselect.php
public function registerAssets(){
        $view = $this->getView();
        AdminUIMultiselect::register($view);
        //$id = $this->options['id'];
        $inputId = Html::getInputId($this->model,  $this->attribute);
        $js = '$("#'.$inputId.'").asmSelect({
				addItemTarget: \'bottom\',
				animate: true,
				highlight: false,
				sortable: true,
                                selectClass:"form-control asmSelect"
			});';
        
        $view->registerJs($js);
    }
public function registerAssets(){
        $view = $this->getView();
        AdminUIMultiselect::register($view);
        //$id = $this->options['id'];
        $inputId = Html::getInputId($this->model,  $this->attribute);
        $js = '$("#'.$inputId.'").asmSelect({
				addItemTarget: \'bottom\',
				animate: true,
				highlight: false,
				sortable: true,
                                selectClass:"form-control asmSelect"
			});';
        
        $view->registerJs($js);
    }
Registers the needed assets