static WALChannelBuilder builder(String path) {
        return new WALChannelBuilder(path);
    }
There are two implementations of WALChannel:
1. WALFileChannel based on file system, which calls fsync after each write to ensure data is flushed to disk.
2. WALBlockDeviceChannel based on block device, which uses O_DIRECT to bypass page cache.
s3stream/src/main/java/com/automq/stream/s3/wal/util/WALChannel.java