private void btnRandomTicket_Tapped(object sender, TappedRoutedEventArgs e)
        {
            var      mode       = AppLogic.Enums.QuestionsGenerationMode.RandomTicket;
            var      parameters = new SessionParameters(mode, false, null);
            ISession session;
            var      creationResult = SessionFactory.CreateSession(parameters, out session);

            if (creationResult == AppLogic.Enums.ParametersValidationResult.Valid)
            {
                this.Frame.Navigate(typeof(QuestionPage), Serializer.SerializeToString(session));
            }
            else
            {
                throw new Exception("This should never happen! Developers, please check parameters creation logic (2)");
            }
        }
        private void btnStart_Click(object sender, RoutedEventArgs e)
        {
            //creating parameters...
            var      mode           = AppLogic.Enums.QuestionsGenerationMode.SelectedTickets;
            var      ticketNums     = listTickets.SelectedItems.Cast <SQLiteShared.Models.Tickets>().Select(ticket => ticket.num).ToArray();
            var      shuffleChecked = Convert.ToBoolean(btnRandomTicket.Tag);
            var      parameters     = new SessionParameters(mode, shuffleChecked, ticketNums);
            ISession session;
            //creating session...
            var creationResult = SessionFactory.CreateSession(parameters, out session);

            if (creationResult == AppLogic.Enums.ParametersValidationResult.Valid)
            {
                this.Frame.Navigate(typeof(QuestionPage), Serializer.SerializeToString(session));
            }
            else
            {
                throw new Exception("This should never happen! Developers, please check parameters creation logic");
            }
        }