public void unmap(T target)
    {
        Set<I> items = reverseMap.get(target);
        items.forEach((i)->mapSet.removeItem(i, target));
        reverseMap.remove(target);
    }
public void unmap ( T target ) { Set < I > items = reverseMap . get ( target ) ; items . forEach ( ( i ) -> mapSet . removeItem ( i , target ) ) ; reverseMap . remove ( target ) ; }
Remove all mappings to target
@param target