code: public function run()
      {
          if (empty($this->links)) {
              return;
          }
          $links = [];
          if ($this->homeLink === null) {
              $links[] = $this->renderItem([
                  'label' => Yii::t('yii', 'Home'),
                  'url' => Yii::$app->homeUrl,
                  'options' => ['class'=>'fa fa-dashboard']
              ], $this->itemTemplate);
          } elseif ($this->homeLink !== false) {
              $links[] = $this->renderItem($this->homeLink, $this->itemTemplate);
          }
          foreach ($this->links as $link) {
              if (!is_array($link)) {
                  $link = ['label' => $link];
              }
              $links[] = $this->renderItem($link, isset($link['url']) ? $this->itemTemplate : $this->activeItemTemplate);
          }
          echo Html::tag($this->tag, implode('', $links), $this->options);
      }
docs: Renders the widget.