| Gets a view of this map where the keys and values are reversed.
Changes to one map will be visible in the other and vice versa.
This enables both directions of the map to be accessed equally.
Implementations should seek to avoid creating a new object every time this
method is called. See AbstractMap.values() etc. Calling this
method on the inverse map should return the original.
Implementations must return a SortedBidiMap instance,
usually by forwarding to inverseSortedBidiMap().
an inverted bidirectional map |