docs: public void add(final DataPoints dps) {
      metric_uids.add(dps.metricUID());
      
      // TODO - tags intersection
      
      for (final byte[] tagk : dps.getAggregatedTagUids()) {
        aggregated_tags.add(tagk);
      }
      
      tsuids.addAll(dps.getTSUIDs());
      // TODO - this ain't right. We need to number of dps emitted from HERE. For
      // now we'll just take the first dps size. If it's downsampled then this
      // will be accurate.
      //size += dps.size();
      // TODO - restore when this is faster
      //raw_size += dps.aggregatedSize();
    }