/**
     * @return string
     */
    public function getTaxonomyCategoryIdentifier()
    {
        if( $this->taxonomyCategory )
            return $this->taxonomyCategory->attribute('identifier');

        return null;
    }
    /**
     * return the mapping with taxonomies and field name in solr
     * @return array
     */
    private function addMappingTaxonomies()
    {
        $fields = array();
        foreach(TaxonomyCategory::getAllCategories() as $category)
        {
            // specific case about PFR refactor #40868
            if($category != "language")
                $fields[$category] = sprintf("subattr_%s___source_id____s", $category);
        }

        return $fields;
    }