protected function getFilterTag($facetConfiguration, $keepAllFacetsOnSelection)
    {
        $tag = '';
        if ($facetConfiguration['keepAllOptionsOnSelection'] == 1 || $facetConfiguration['addFieldAsTag'] == 1 || $keepAllFacetsOnSelection) {
            $tag = '{!tag=' . addslashes($facetConfiguration['field']) . '}';
        }

        return $tag;
    }