private TwoWayDictionary(TwoWayDictionary <U, T> reversed)
{
_forwards = reversed._backwards;
_backwards = reversed._forwards;
Reversed = reversed;
}
public TwoWayDictionary()
{
_forwards = new Dictionary <T, U>();
_backwards = new Dictionary <U, T>();
Reversed = new TwoWayDictionary <U, T>(this);
}