public void CountNumberOfLuckyTickets_Piter_ReturnsNumberOfTickets(int digits, int expected)
        {
            // Arrange
            LuckyTicketCounter ticketCounter = new LuckyTicketCounter(new LuckyTicketPeter(), digits);

            // Act
            int actual = ticketCounter.CountNumberOfLuckyTickets();

            // Assert
            Assert.AreEqual(expected, actual);
        }