| Package | Description | 
|---|---|
| java.util.concurrent | Utility classes commonly useful in concurrent programming. | 
| Modifier and Type | Method and Description | 
|---|---|
| ConcurrentHashMap.KeySetView<K,V> | ConcurrentHashMap. keySet()Returns a  Setview of the keys contained in this map. | 
| ConcurrentHashMap.KeySetView<K,V> | ConcurrentHashMap. keySet(V mappedValue)Returns a  Setview of the keys in this map, using the
 given common mapped value for any additions (i.e.,Collection.add(E)andCollection.addAll(Collection)). | 
| static <K> ConcurrentHashMap.KeySetView<K,Boolean> | ConcurrentHashMap. newKeySet()Creates a new  Setbacked by a ConcurrentHashMap
 from the given type toBoolean.TRUE. | 
| static <K> ConcurrentHashMap.KeySetView<K,Boolean> | ConcurrentHashMap. newKeySet(int initialCapacity)Creates a new  Setbacked by a ConcurrentHashMap
 from the given type toBoolean.TRUE. | 
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