@Override
    public long getCommitLast() {
        return start + flushedSize.get();
    }
Return the position that have been flushed to disk.

@return the position that have been flushed to disk
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/broker/msgstore/disk/FileSegment.java