protected function renderSearchInput()
    {
        $lines = [];
        $lines[] = Html::beginTag('div', ['class' =>'ui icon search input']);
        $lines[] = Html::tag('i', '', ['class' => 'search icon']);
        $lines[] = Html::input('text', $this->getId() . '-search', '', $this->searchInputOptions);
        $lines[] = Html::endTag('div');
        $lines[] = Html::tag('div', '', ['class' => 'divider']);
        return implode("\n", $lines);
    }