code: public function registerAssetFiles($view)
      {
          $manager = $view->getAssetManager();
          foreach ($this->js as $js) {
              if (is_array($js)) {
                  $file = array_shift($js);
                  $options = ArrayHelper::merge($this->jsOptions, $js);
                  $view->registerJsFile($manager->getAssetUrl($this, $file), $options);
              } else {
                  if ($js !== null) {
                      $view->registerJsFile($manager->getAssetUrl($this, $js), $this->jsOptions);
                  }
              }
          }
          foreach ($this->css as $css) {
              if (is_array($css)) {
                  $file = array_shift($css);
                  $options = ArrayHelper::merge($this->cssOptions, $css);
                  $view->registerCssFile($manager->getAssetUrl($this, $file), $options);
              } else {
                  if ($css !== null) {
                      $view->registerCssFile($manager->getAssetUrl($this, $css), $this->cssOptions);
                  }
              }
          }
      }
docs: Registers the CSS and JS files with the given view.
  @param \yii\web\View $view the view that the asset files are to be registered with.