public void process_order_should_succeed()
        {
            //Arrange
            User.IncreaseFunds(100);
            User.Activate();

            //Act
            OrderProcessor.ProcessOrder(User.Email, Order.Id);

            //Assert

            DatabaseMock.Verify(x => x.GetUser(User.Email), Times.Once());
            DatabaseMock.Verify(x => x.GetOrder(Order.Id), Times.Once());
            Order.IsPurchased.Should().BeTrue();
        }
        public void process_order_should_succeed()
        {
            //Arrange
            User.IncreaseFunds(100);

            //Act
            OrderProcessor.ProcessOdrer(User.Email, Order.Id);

            //Assert

            //checks whether the method has been performed
            DatabaseMock.Verify(x => x.GetUser(It.IsAny <string>()), Times.Once);
            DatabaseMock.Verify(x => x.GetOrder(It.IsAny <int>()), Times.Once);

            Assert.IsTrue(Order.IsPurchased);

            //fluent assertion
            Order.IsPurchased.Should().BeTrue();
        }