public void TestCalculateTotalBillSmall()
 {
     //Testing CalculateTotalBill with small numbers
     TestCalculateTotalBillSmall calculateTotalBill = new CalculateTotalBill();
     decimal expected = 1;
     decimal actual = calculateTotalBill.Add(0, 1);
     Assert.AreEqual(expected, actual);
 }
 public void TestCalculateTotalBillLarge()
 {
     //Testing CalculateTotalBill with large numbers
     TestCalculateTotalBillLarge calculateTotalBill = new CalculateTotalBill();
     decimal expected = 1000000000;
     decimal actual = calculateTotalBill.Add(500000000, 500000000);
     Assert.AreEqual(expected, actual);
 }