docs: static SnapshotInfo consolidateSnapshotInfos(Collection<SnapshotInfo> lastSnapshot)
      {
          SnapshotInfo chosen = null;
          if (lastSnapshot != null) {
              Iterator<SnapshotInfo> i = lastSnapshot.iterator();
              while (i.hasNext()) {
                  SnapshotInfo next = i.next();
                  if (chosen == null) {
                      chosen = next;
                  } else if (next.hostId < chosen.hostId) {
                      next.partitionToTxnId.putAll(chosen.partitionToTxnId);
                      chosen = next;
                  }
                  else {
                      // create a full mapping of txn ids to partition ids.
                      chosen.partitionToTxnId.putAll(next.partitionToTxnId);
                  }
              }
          }
          return chosen;
      }