@Override
    public CompletableFuture<Boolean> removeParent(ImmutableContextSet contexts, LPSubjectReference parent) {
        Set<LPSubjectReference> set = this.parents.get(contexts);
        boolean b = set != null && set.remove(parent);
        if (b) {
            this.service.invalidateAllCaches();
        }
        return CompletableFuture.completedFuture(b);
    }
In-memory implementation of {@link LPSubjectData}.
sponge/src/main/java/me/lucko/luckperms/sponge/service/model/calculated/CalculatedSubjectData.java