public function check()
 {
     RequestCheckUtil::checkNotNull($this->fields, "fields");
     RequestCheckUtil::checkMaxListSize($this->numIids, 50, "numIids");
     RequestCheckUtil::checkMaxListSize($this->trackIids, 50, "trackIids");
 }
 public function check()
 {
     RequestCheckUtil::checkNotNull($this->fields, "fields");
     RequestCheckUtil::checkMaxListSize($this->sellerNicks, 10, "sellerNicks");
     RequestCheckUtil::checkMaxListSize($this->sids, 10, "sids");
 }