public function searchPickupPointsByText($query_text, $service_provider = null, $limit = 5)
    {
        if ( $query_text == null || trim($query_text) == '' ) {
            return '[]';
        }

        $post_params = array(
            'query'             => (string) $query_text,
            'service_provider'  => (string) $service_provider,
            'limit'             => (int) $limit
        );

        return $this->doPost('/pickup-points/search', $post_params);
    }