@Override
    public void accept(Path t) {
      files.add(t);
    }
Use this counter to track concurrent puts. If TRACE-log is enabled, if we are over the
threshold set by hbase.region.store.parallel.put.print.threshold (Default is 50) we will log a
message that identifies the Store experience this high-level of concurrency.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java