public void UndoScoredTossup()
        {
            TossupBonusPhaseState phaseState = new TossupBonusPhaseState();

            phaseState.AddBuzz(DefaultBuzz);
            Assert.IsTrue(phaseState.TryScoreBuzz(-5), "Scoring the first buzz should succeed");

            Assert.IsTrue(
                phaseState.AlreadyBuzzedPlayerIds.Contains(DefaultBuzz.UserId),
                "Default player not in the list of already buzzed players");
            Assert.AreEqual(1, phaseState.Actions.Count, "Unexpected number of buzzes recorded");

            ulong  secondBuzzPlayerId = DefaultBuzz.UserId + 1;
            string secondTeamId       = $"{DefaultBuzz.TeamId}1";
            Buzz   incorrectBuzz      = new Buzz()
            {
                TeamId            = secondTeamId,
                PlayerDisplayName = "Bob",
                UserId            = secondBuzzPlayerId,
                Timestamp         = DateTime.Now + TimeSpan.FromSeconds(1)
            };

            phaseState.AddBuzz(incorrectBuzz);
            Assert.IsTrue(phaseState.TryScoreBuzz(0), "Scoring the second buzz should succeed");
            Assert.IsTrue(
                phaseState.AlreadyBuzzedPlayerIds.Contains(secondBuzzPlayerId),
                "Second player not in the list of already buzzed players");
            Assert.AreEqual(2, phaseState.Actions.Count, "Unexpected number of buzzes recorded after the second buzz");

            phaseState.Undo(out ulong?userId);
            Assert.AreEqual(secondBuzzPlayerId, userId, "Unexpected userId returned by Undo");
            Assert.IsTrue(
                phaseState.AlreadyScoredTeamIds.Contains(DefaultBuzz.TeamId),
                "Default player not in the list of already scored teams after the first undo");
            Assert.IsFalse(
                phaseState.AlreadyScoredTeamIds.Contains(secondTeamId),
                "Second player not in the list of already scored teams after the first undo");
            Assert.AreEqual(1, phaseState.Actions.Count, "Unexpected number of buzzes recorded after the first undo");

            phaseState.Undo(out userId);
            Assert.AreEqual(DefaultBuzz.UserId, userId, "Unexpected userId returned by Undo");
            Assert.IsFalse(
                phaseState.AlreadyScoredTeamIds.Contains(DefaultBuzz.TeamId),
                "Default player not in the list of already scored teams after the second undo");
            Assert.AreEqual(0, phaseState.Actions.Count, "Unexpected number of buzzes recorded after the second undo");
        }
        public void UndoBonusAfterScoringIt()
        {
            TossupBonusPhaseState phaseState = CreatePhaseInBonusStage();

            Assert.IsTrue(phaseState.TryScoreBonus("0"), "Scoring the bonus should've succeeded");
            Assert.AreEqual(
                TossupBonusPhaseState.DefaultBonusLength, phaseState.BonusScores.Count, "We should have three parts scored");

            phaseState.Undo(out ulong?userId);
            Assert.IsNull(userId, "userId should be null (scoring a bonus)");
            Assert.AreEqual(0, phaseState.BonusScores.Count, "Bonus scores should be cleared, but not gone");
            Assert.AreEqual(PhaseStage.Bonus, phaseState.CurrentStage, "Unexpected stage after first undo");
            Assert.IsTrue(
                phaseState.AlreadyScoredTeamIds.Contains(DefaultBuzz.TeamId),
                "Default player not in the list of already scored teams after the second undo");
            Assert.AreEqual(1, phaseState.Actions.Count, "Unexpected number of buzzes recorded after the second undo");

            phaseState.Undo(out userId);
            Assert.AreEqual(DefaultBuzz.UserId, userId, "userId should not be null after undoing the bonus score");
            Assert.IsNull(phaseState.BonusScores, "Bonus scores should be gone");
            Assert.AreEqual(PhaseStage.Tossup, phaseState.CurrentStage, "Unexpected stage after second undo");
        }