public static PatternTreeMap<ModEntry, ModsSerializer> getModsPatternTreeMap() {
    return new PatternTreeMap<>(
        HashSet::new, (mod, set) -> set.add(mod), null, ModsSerializer.getInstance());
  }
This PatternTreeMap is used to manage Modification. The append will merge of Modification that
intersect.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/datastructure/PatternTreeMapFactory.java