public Set<LPSubjectReference> resolveParents(QueryOptions filter) {
        // get relevant entries
        SortedMap<ImmutableContextSet, Set<LPSubjectReference>> sorted = new TreeMap<>(ContextSetComparator.reverse());
        for (Map.Entry<ImmutableContextSet, Set<LPSubjectReference>> entry : this.parents.entrySet()) {
            if (!filter.satisfies(entry.getKey(), defaultSatisfyMode())) {
                continue;
            }

            sorted.put(entry.getKey(), entry.getValue());
        }

        // flatten
        Set<LPSubjectReference> result = new LinkedHashSet<>();
        for (Set<LPSubjectReference> set : sorted.values()) {
            result.addAll(set);
        }
        return result;
    }
In-memory implementation of {@link LPSubjectData}.
sponge/src/main/java/me/lucko/luckperms/sponge/service/model/calculated/CalculatedSubjectData.java