Being able to learn cards to both sides

When you learn cards right now, it will only let you learn the "direction" you made/imported them in the flashcard creator. For example: if I have 10 words from German to English, it will only give the definition in German and I have to give the answer in English. My request is that I can toggle "learn to both sides" when I start studying. That way, it would let me study the cards from German to English, and when I master them, it will make me study the cards from English to German. This is handy, especially for students who have to learn cards to both sides and don't want to create the flashcards twice (German > Engisch and English > German).