public void addVersionDelete(ExtendedCell cell) {
      SortedSet<Long> set = deletesMap.get(cell.getTimestamp());
      if (set == null) {
        set = new TreeSet<>();
        deletesMap.put(cell.getTimestamp(), set);
      }
      set.add(cell.getSequenceId());
      // The init set should be the puts whose mvcc is smaller than this Delete. Because
      // there may be some Puts masked by them. The Puts whose mvcc is larger than this Delete can
      // not be copied to this node because we may delete one version and the oldest put may not be
      // masked.
      SortedSet<Long> nextValue = mvccCountingMap.ceilingEntry(cell.getSequenceId()).getValue();
      SortedSet<Long> thisValue = new TreeSet<>(nextValue.headSet(cell.getSequenceId()));
      mvccCountingMap.put(cell.getSequenceId(), thisValue);
    }
A data structure which contains infos we need that happens before this node's mvcc and after
the previous node's mvcc. A node means there is a version deletion at the mvcc and ts.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/querymatcher/NewVersionBehaviorTracker.java