void add(SortableFeature entry) {
      numFeaturesProcessed.incrementAndGet();
      long key = entry.key();
      if (extractHasGroupFromKey(key)) {
        byte thisLayer = extractLayerIdFromKey(key);
        if (counts == null) {
          counts = Hppc.newLongLongHashMap();
          lastLayer = thisLayer;
        } else if (thisLayer != lastLayer) {
          lastLayer = thisLayer;
          counts.clear();
        }
        var groupInfo = peekAtGroupInfo(entry.value());
        long old = counts.getOrDefault(groupInfo.group(), 0);
        if (groupInfo.limit() > 0 && old >= groupInfo.limit()) {
          // discard if there are to many features in this group already
          return;
        }
        counts.put(groupInfo.group(), old + 1);
      }
      entries.add(entry);
    }
Returns true if {@code other} contains features with identical layer, geometry, and attributes, as this tile -
even if the tiles have separate coordinates.
<p>
Used as an optimization to avoid re-encoding the same ocean tiles over and over again.
planetiler-core/src/main/java/com/onthegomap/planetiler/collection/FeatureGroup.java