Returns the key corresponding to this entry.
Returns the value corresponding to this entry. If the mapping has been removed from the backing map (by the iterator's <tt>remove</tt> operation), the results of this call are undefined.
Replaces the value corresponding to this entry with the specified value (optional operation). (Writes through to the map.) The behavior of this call is undefined if the mapping has already been removed from the map (by the iterator's <tt>remove</tt> operation).