A SetMultimap whose set of values for a given key are kept sorted; that is, they comprise a SortedSet. It cannot hold duplicate key-value pairs; adding a key-value pair that's already in the multimap has no effect. This interface does not specify the ordering of the multimap's keys. See the Multimap<K,V> documentation for information common to all multimaps. The #get, #removeAll, and #replaceValues methods each return a SortedSet of values, while entries() returns a Set of map entries. Though the method signature doesn't say so explicitly, the map returned by #asMap has SortedSet values. See the Guava User Guide article on Multimap.
A concurrent map which forwards all its method calls to another concurrent map. Subclasses should override one or more methods to modify the behavior of the backing map as desired per the decorator pattern. default method warning: This class forwards calls to only some default methods. Specifically, it forwards calls only for methods that existed before default methods were introduced. For newer methods, like forEach, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingConcurrentMap.
A NavigableMap whose contents will never change, with many other important properties detailed at ImmutableCollection<E>. Warning: as with any sorted collection, you are strongly advised not to use a Comparator or Comparable type whose comparison behavior is inconsistent with equals. That is, a.compareTo(b) or comparator.compare(a, b) should equal zero if and only if a.equals(b). If this advice is not followed, the resulting map will not correctly obey its specification. See the Guava User Guide article on immutable collections.
A ListMultimap<K,V> whose contents will never change, with many other important properties detailed at ImmutableCollection<E>. See the Guava User Guide article on immutable collections.