* in combination with the default writelock timeout*/
config.setWriteLockTimeout(5000);
config.setUseCompoundFile(this.compoundOnFlush);
// Warm-up hook for newly-merged segments. Warming up segments here is better since it will be performed at the end
// of the merge operation and won't slow down _refresh
config.setMergedSegmentWarmer(new IndexReaderWarmer() {
@Override
public void warm(LeafReader reader) throws IOException {
try {
assert isMergedSegment(reader);
if (warmer != null) {