private List <DLL.Appointment> GetAppointments(int userId, int opponentId, out bool opponentAvailabilitySet)
        {
            List <DLL.Appointment> appointments = new List <DLL.Appointment>();

            opponentAvailabilitySet = false;
            using (FlexibleTennisLeagueDataContext dataContext = new FlexibleTennisLeagueDataContext())
            {
                appointments = dataContext.SelectAppointmentsByUserIdOpponentId(StoredData.User.UserId, opponentId).ToList();
                //Get availability for current user
                List <SelectAvailabilitiesByUserIdResult> availability = dataContext.SelectAvailabilitiesByUserId(StoredData.User.UserId).ToList();
                if (availability.Count > 0)
                {
                    appointments = CombineAppointmentsWithAvailability(availability, appointments, StoredData.User.UserId);
                }

                //Get availability for opponent
                List <SelectAvailabilitiesByUserIdResult> opponentAvailability = dataContext.SelectAvailabilitiesByUserId(opponentId).ToList();
                if (opponentAvailability.Count > 0)
                {
                    appointments            = CombineAppointmentsWithAvailability(opponentAvailability, appointments, opponentId);
                    opponentAvailabilitySet = true;
                }
            }
            return(appointments);
        }