RequestBatch::merge

public function merge(ProtobufMessage $message)
    {
        if ( ! $message instanceof BitrixPullProtobufRequestBatch) {
            throw new InvalidArgumentException(sprintf('Argument 1 passed to %s must be a %s, %s given', __METHOD__, __CLASS__, get_class($message)));
        }

        $this->requests = ($message->requests !== null) ? $message->requests : $this->requests;
    }