public void GetPendingExpenses()
        {
            // Arrange
            MonthSummary summary = BuildSummary();

            // Act
            var statements = summary.GetPendingExpenses();

            // Assert
            Assert.Equal(2, statements.Count);
            Assert.Equal(621.10m, statements.Sum(x => x.Amount.Value));
        }
 private IReadOnlyList <StatementDto> FormatPendingStatements() => summary
 .GetPendingExpenses()
 .Select(x => new StatementDto(x.Id, x.DueDate, x.Description, x.Amount, x.Category.Name))
 .ToList();