@Nonnull @Override public Optional<SingleFeatureBean> containerOf(Id id) { checkNotNull(id, "id"); return Optional.ofNullable(containers().get(id)); }
@Override public void removeContainer(Id id) { checkNotNull(id, "id"); containers().remove(id); }
@Override public void containerFor(Id id, SingleFeatureBean container) { checkNotNull(id, "id"); checkNotNull(container, "container"); containers().put(id, container); }