private static long getEffectiveMs(final Meta meta) {
        final long effectiveMs;
        // When there is not effectiveMs for a stream we have to fall back on the mandatory createMs
        if (meta.getEffectiveMs() != null) {
            effectiveMs = meta.getEffectiveMs();
        } else {
            LOGGER.debug(() -> "Using createMs for effectiveMs for id " + meta.getId());
            effectiveMs = meta.getCreateMs();
        }
        return effectiveMs;
    }
Only to be used as a threshold in {@link NavigableSet#floor(Object)} navigation
where we only care about the effectiveMs.
stroom-meta/stroom-meta-api/src/main/java/stroom/meta/api/EffectiveMeta.java