private void FetchStartBossStages()
 {
     foreach (var stage in ArenaRewardPerLevelRange.ArenaStages)
     {
         ArenaStages.Add(stage);
     }
     SelectedStartStage = ArenaStages.FirstOrDefault();
 }
        private void FetchPossibleEndStages()
        {
            PossibleEndStages.Clear();
            int stage    = SelectedStartStage;
            int maxStage = SelectedStartStage + 3;

            do
            {
                if (ArenaStages.Contains(stage))
                {
                    PossibleEndStages.Add(stage);
                }
                stage++;
            } while (stage <= maxStage);
            SelectedEndStage = PossibleEndStages.LastOrDefault();
        }