protected void addTimeStamp() {
      if (loaded) {
        if (firstTSidx == -1) {
          firstTSidx = archive.getTimeStamps().getSize() - 1;
        }
        for (final SimpleValue value : values) {
          if (value != null) {
            value.addSample();
          }
        }
      }
    }
Returns true if archive might still have future samples for this instance.
geode-core/src/main/java/org/apache/geode/internal/statistics/StatArchiveReader.java