src/Widgets/Bootstrap/Carousel.php
public function init()
    {
        parent::init();
        Html::addCssClass($this->options, ['widget' => 'carousel slide']);
        if (isset($this->controls) && empty($this->controls)) {
            $this->controls[] = Html::tag('span', '', ['class' => 'carousel-control-prev-icon'])
                . $this->htmlHlp->tag('span', $this->controlsLabels[0], ['class' => 'sr-only']);
            $this->controls[] = Html::tag('span', '', ['class' => 'carousel-control-next-icon'])
                . $this->htmlHlp->tag('span', $this->controlsLabels[1], ['class' => 'sr-only']);
        }
    }
public function init()
    {
        parent::init();
        Html::addCssClass($this->options, ['widget' => 'carousel slide']);
        if (isset($this->controls) && empty($this->controls)) {
            $this->controls[] = Html::tag('span', '', ['class' => 'carousel-control-prev-icon'])
                . $this->htmlHlp->tag('span', $this->controlsLabels[0], ['class' => 'sr-only']);
            $this->controls[] = Html::tag('span', '', ['class' => 'carousel-control-next-icon'])
                . $this->htmlHlp->tag('span', $this->controlsLabels[1], ['class' => 'sr-only']);
        }
    }
Initializes the widget.