"nullness", // too much trouble for the payoff
})
@NullUnmarked // TODO(cpovirk): Annotate for nullness.
final class MapMakerInternalMap<
        K,
        V,
        E extends MapMakerInternalMap.InternalEntry<K, V, E>,
        S extends MapMakerInternalMap.Segment<K, V, E, S>>
    extends AbstractMap<K, V> implements ConcurrentMap<K, V>, Serializable {

  /*