protected function renderBehaviourScrollbar()
    {

        if (in_array( self::BEHAVIOUR_SCROLLBAR, $this->behaviours )) {
            $scrollbarOptions = $this->scrollbarOptions;
            $scrollbarTag     = ArrayHelper::remove( $scrollbarOptions, 'tag', 'div' );

            if ( ! isset( $this->pluginOptions[self::OPTION_SCROLLBAR] )) {
                $this->pluginOptions[self::OPTION_SCROLLBAR] = "#" . $scrollbarOptions["id"];
            }

            return Html::tag( $scrollbarTag, '', $scrollbarOptions );
        }

        return '';
    }