private static NavigableSet<EffectiveMeta> createTreeSet() {
        // We control the comparator so EffectiveMetaSet can be sure how things are
        // being sorted/compared.
        return new TreeSet<>(EFF_TIME_COMPARATOR);
    }
Create a {@link Stream} {@link Collector} for creating an {@link EffectiveMetaSet}
from a {@link Stream} of {@link EffectiveMeta}.

@param feedName The feed name for all {@link EffectiveMeta} items.
@param typeName The stream type name for all {@link EffectiveMeta} items.
stroom-meta/stroom-meta-api/src/main/java/stroom/meta/api/EffectiveMetaSet.java