public int[,] GenerateRandomBingoCardNumbers()
        {
            var ng = new BingoNumbersGenerator();
            var randomCardNumbers = new[, ]
            {
                { ng.GenerateUniqueNumberForLetter(BingoLetter.B), ng.GenerateUniqueNumberForLetter(BingoLetter.I), ng.GenerateUniqueNumberForLetter(BingoLetter.N), ng.GenerateUniqueNumberForLetter(BingoLetter.G), ng.GenerateUniqueNumberForLetter(BingoLetter.O) },
                { ng.GenerateUniqueNumberForLetter(BingoLetter.B), ng.GenerateUniqueNumberForLetter(BingoLetter.I), ng.GenerateUniqueNumberForLetter(BingoLetter.N), ng.GenerateUniqueNumberForLetter(BingoLetter.G), ng.GenerateUniqueNumberForLetter(BingoLetter.O) },
                { ng.GenerateUniqueNumberForLetter(BingoLetter.B), ng.GenerateUniqueNumberForLetter(BingoLetter.I), ng.GenerateUniqueNumberForLetter(BingoLetter.N), ng.GenerateUniqueNumberForLetter(BingoLetter.G), ng.GenerateUniqueNumberForLetter(BingoLetter.O) },
                { ng.GenerateUniqueNumberForLetter(BingoLetter.B), ng.GenerateUniqueNumberForLetter(BingoLetter.I), ng.GenerateUniqueNumberForLetter(BingoLetter.N), ng.GenerateUniqueNumberForLetter(BingoLetter.G), ng.GenerateUniqueNumberForLetter(BingoLetter.O) },
                { ng.GenerateUniqueNumberForLetter(BingoLetter.B), ng.GenerateUniqueNumberForLetter(BingoLetter.I), ng.GenerateUniqueNumberForLetter(BingoLetter.N), ng.GenerateUniqueNumberForLetter(BingoLetter.G), ng.GenerateUniqueNumberForLetter(BingoLetter.O) }
            };

            return(randomCardNumbers);
        }
        public BingoBall GenerateRandomBingoBall()
        {
            if (!CanGenerateBalls())
            {
                throw new Exception("All balls were already generated");
            }
            var randomLetter = GenerateRandomBingoLetter();

            if (!_numbersGenerator.CanGenerateNumberForLetter(randomLetter))
            {
                return(GenerateRandomBingoBall());
            }
            var randomNumber = _numbersGenerator.GenerateUniqueNumberForLetter(randomLetter);

            return(new BingoBall(randomLetter, randomNumber));
        }