Before revision: The ConcurrentNavigableMap interface is a subinterface of java.util.Map but has special ordering and concurrency methods: an example implementation is java.util.concurrent.ConcurrentSkipListMap.
After revision: The ConcurrentNavigableMap interface is a subinterface of java.util.Map but has special ordering and concurrency methods: this is the same API as java.util.concurrent.ConcurrentSkipListMap.