static void Main(string[] args)
        {
            var disease         = new Disease("Cancer", true);
            var disease1        = new Disease("HIV", true);
            var historyInstance = new PatientHistory();
            var tony            = new NationalPatient(74565, "Tony", "Stark");
            var gaurav          = new InternationalPatient(54949, "Gaurav", "Rana");

            Console.WriteLine(gaurav.FirstName + "," + gaurav.LastName + ", "
                              + gaurav.PatientID + "," + gaurav.InsuraceDetail);

            historyInstance.AddPatientTransaction(tony, new DateTime(2015, 03, 21), disease);
            Console.WriteLine("Disease: " + historyInstance.ReturnDiseaseLog(tony, new DateTime(2015, 03, 21)));

            Console.WriteLine("Testing return patient history: " +
                              historyInstance.ReturnPatientDetails(new DateTime(2015, 03, 21), disease)
                              .PatientID + ", " + historyInstance.ReturnPatientDetails(new DateTime(2015, 03, 21), disease)
                              .FirstName + ", " + historyInstance.ReturnPatientDetails(new DateTime(2015, 03, 21), disease)
                              .LastName);

            historyInstance.AddPatientTransaction(tony, new DateTime(2015, 04, 22), disease1);
            historyInstance.GetAllPatientTransactions();
            Console.WriteLine(historyInstance.NumberOfTransactions());

            historyInstance.RemovePatientTransaction(tony, new DateTime(2015, 03, 21));
            historyInstance.GetAllPatientTransactions();
            Console.WriteLine(historyInstance.NumberOfTransactions());

            Patient pa = new NationalPatient();

            var pm = new PatientManagement();

            pm.AddPatient(tony);
            pm.AddPatient(pa);

            Console.WriteLine(pm.PatientCount());
            //pm.GetAllPatients();
        }