class FlashCard(val langFromTo: (String,String), val question: String, val answer: String)
// np. FlashCard( ("POL", "ENG"), "zielony", "green")

class StackIndetifier(val name: String)

trait FlashCardsDBConnector {
    def addCard(card: FlashCard, stack: StackIndetifier)
    def removeCard(card: FlashCard, stack: StackIndetifier)
    def swapCard(from: FlashCard, to: FlashCard, stack: StackIndetifier)

    def getCardsFromStack(stack: StackIndetifier)
}
trait CardsStack(val name: String, val cards: Array[FlashCard], DBConnector: FlashCardsDBConnector) {
    def addCard(card: FlashCard)
    def removeCard(card: FlashCard)
    def swapCard(from: FlashCard)

    def getAll()
    def getAllSchuffled()
    def getNext()
    def getRandom()
}
// np. CardsStack(val name: String, val cards: Array[FlashCard], DBConnector: FlashCardsDBConnector)