Returns a {@link Collection} view of the values contained in this map.
The collection's iterator returns the values in ascending order
of the corresponding keys.
The collection is backed by the map, so changes to the map are
reflected in the collection, and vice-versa. If the map is
modified while an iteration over the collection is in progress
(except through the iterator's own {@code remove} operation),
the results of the iteration are undefined. The collection
supports element removal, which removes the corresponding
mapping from the map, via the {@code Iterator.remove},
{@code Collection.remove}, {@code removeAll},
{@code retainAll} and {@code clear} operations. It does not
support the {@code add} or {@code addAll} operations.
@return a collection view of the values contained in this map,
sorted in ascending key order
Returns a {@link Collection} view of the values contained in this map. The collection's iterator returns the values in ascending order of the corresponding keys. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own {@code remove} operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the {@code Iterator.remove}, {@code Collection.remove}, {@code removeAll}, {@code retainAll} and {@code clear} operations. It does not support the {@code add} or {@code addAll} operations.
@return a collection view of the values contained in this map, sorted in ascending key order