public long[] getAllActiveProcIds() {
    return map.values().stream().map(BitSetNode::getActiveProcIds).filter(p -> p.length > 0)
      .flatMapToLong(LongStream::of).toArray();
  }
Will be used when there are too many proc wal files. We will rewrite the states of the active
procedures in the oldest proc wal file so that we can delete it.
@return all the active procedure ids in this tracker.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/store/wal/ProcedureStoreTracker.java