public boolean isLoggable(LogRecord record) {
        String msg = record.getMessage();
        if (msg != null && recent.contains(msg)) {
            return false;  // duplicate
        } else {
            recent.addLast(msg);
            if (recent.size() > maxMessages) {
                recent.removeFirst();
            }
            return true;   // new message
        }
    }
A filter for log messages that prevents the most recently published messages
to be published again. See bug #461290.

@author gjoranv
config-model/src/main/java/com/yahoo/vespa/model/RecentLogFilter.java