public void SimpleCalculation2()
        {
            var record11 = new ReceiptRecord("Глеб", 10);
            var record12 = new ReceiptRecord("Данил", 123);
            var record13 = new ReceiptRecord("Альбина", 100);
            var receipt1 = new Receipt { Payer = "Глеб", Records = new[] { record11, record12, record13 } };

            var record23 = new ReceiptRecord("Альбина", 30);
            var receipt2 = new Receipt { Payer = "Данил", Records = new[] { record23 } };

            var calculator = new ReceiptsCalculator();
            Transfer[] transactions = calculator.Calculate(new[] { receipt1, receipt2 });

            transactions.First(x => x.From == "Альбина").Amount.Should().Be(130);
            transactions.First(x => x.From == "Данил").Amount.Should().Be(93);
        }
        public void SimpleCalculation()
        {
            var record12 = new ReceiptRecord("Данил", 100);
            var record13 = new ReceiptRecord("Альбина", 50);
            var receipt1 = new Receipt {Payer = "Глеб", Records = new[] {record12, record13}};

            var record21 = new ReceiptRecord("Глеб", 10);
            var record22 = new ReceiptRecord("Данил", 260);
            var record23 = new ReceiptRecord("Альбина", 250);
            var receipt2 = new Receipt {Payer = "Данил", Records = new[] {record21, record22, record23}};

            var calculator = new ReceiptsCalculator();
            Transfer[] transactions = calculator.Calculate(new[] { receipt1,receipt2 });

            transactions.First(x => x.To == "Данил").Amount.Should().Be(160);
            transactions.First(x => x.To == "Глеб").Amount.Should().Be(140);
        }