Add the following new defaults on Map:

    default V putIfAbsent(K key, V value) {
    default boolean remove(Object key, Object value) {
    default boolean replace(K key, V oldValue, V newValue) {
    default V replace(K key, V value) {
    default V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
    default V computeIfPresent(K key,
                               BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
    default V compute(K key,
                      BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
    default V merge(K key, V value,
                    BiFunction<? super V, ? super V, ? extends V> remappingFunction) {

Also correponding updates in ConcurrentMap.