pollLast that return and remove the lowest and highest key,
+ * if one exists, else returning null.
*
- * The return values of these methods may be ambiguous in
+ *
The return values of navigation methods may be ambiguous in
* implementations that permit null elements. However, even
* in this case the result can be disambiguated by checking
* contains(null). To avoid such issues, implementations of
@@ -103,6 +106,14 @@ public interface NavigableSet extends
public E pollLast();
/**
+ * Returns an iterator over the elements in this collection, in
+ * descending order.
+ *
+ * @return an Iterator over the elements in this collection
+ */
+ Iterator descendingIterator();
+
+ /**
* Returns a view of the portion of this set whose elements range from
* fromElement, inclusive, to toElement, exclusive. (If
* fromElement and toElement are equal, the returned