@Override
    public CompletableFuture<Boolean> clearParents() {
        if (this.parents.isEmpty()) {
            return CompletableFuture.completedFuture(false);
        } else {
            this.parents.clear();
            this.service.invalidateAllCaches();
            return CompletableFuture.completedFuture(true);
        }
    }
In-memory implementation of {@link LPSubjectData}.
sponge/src/main/java/me/lucko/luckperms/sponge/service/model/calculated/CalculatedSubjectData.java