public void WhenAddingRecordsToInvoiceList_RecordsSouldBeUpdated(List <Record> records)
        {
            // arrange
            var invoiceList = new InvoiceList();

            // act
            foreach (var record in records)
            {
                invoiceList.AddRecord(record);
            }

            // assert
            invoiceList.GetRecords().Should().NotBeEmpty();
            invoiceList.GetRecords().Should().BeEquivalentTo(records);
            invoiceList.CountRecords().Should().Be(records.Count);
        }