public function solr_client() {
        if (!isset($this->_solrclient)) {
            $this->_solrclient = new \Solarium\Client(array(
                'endpoint' => array(
                    'localhost' => array(
                        'host' => $this->_url,
                        'port' => $this->_solr_port,
                        'path' => '/solr/' . $this->_collection . '/'
                    )
                )
            ));
        }

        return $this->_solrclient;
    }