ChannelId::merge

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

        $this->id = ($message->id !== null) ? $message->id : $this->id;
        $this->isPrivate = ($message->isPrivate !== null) ? $message->isPrivate : $this->isPrivate;
        $this->signature = ($message->signature !== null) ? $message->signature : $this->signature;
    }