protected void removeOlderMembers(Set<PersistentMemberID> persistentMemberSet) {
    Map<DiskStoreID, PersistentMemberID> mostRecentMap = new HashMap<>();
    List<PersistentMemberID> idsToRemove = new ArrayList<>();
    for (PersistentMemberID persistentMember : persistentMemberSet) {
      DiskStoreID diskStoreId = persistentMember.getDiskStoreId();
      PersistentMemberID mostRecent = mostRecentMap.get(diskStoreId);
      if (mostRecent == null) {
        mostRecentMap.put(diskStoreId, persistentMember);
      } else {
        PersistentMemberID older = persistentMember;
        boolean persistentMemberIsNewer =
            !persistentMember.isOlderOrEqualVersionOf(mostRecent);
        if (persistentMemberIsNewer) {
          older = mostRecent;
          mostRecentMap.put(diskStoreId, persistentMember);
        }
        idsToRemove.add(older);
      }
    }
    persistentMemberSet.removeAll(idsToRemove);
  }
Given a set of persistent members, if the same member occurs more than once in the set but
with different timestamps, remove the older ones leaving only the most recent.

@param persistentMemberSet The set of persistent members, possibly modified by this method.
geode-core/src/main/java/org/apache/geode/internal/cache/persistence/PersistenceAdvisorImpl.java