public Optional<EffectiveMeta> first() {
        try {
            return Optional.ofNullable(effectiveMetas.first());
        } catch (NoSuchElementException e) {
            return Optional.empty();
        }
    }
@return The {@link EffectiveMeta} with the oldest effectiveTimeMs
stroom-meta/stroom-meta-api/src/main/java/stroom/meta/api/EffectiveMetaSet.java