code: public function getDomainStatistics($domain, $period, $value, $type)
      {
          return json_decode(self::getClient()->getDomainStatistics($this->sn, $domain, $period, $value, $type));
      }
docs: Return CDN statistics for domain $domain
  
  @param string $domain
  @param string $period ("day" | "month" | "week")
  @param string $value ("bandwidth" | "request")
  @param $type ("backend" | "cdn")
  @return array of object statistics