[Solved] NullReferenceException when using Aggregate

[Philip Fourie]

I am getting a NullReferenceException when using the following code.

columns.Bound(o => o.NormalHours)
    .Aggregate(a => a.Sum()).FooterTemplate(@<text>@item.Sum.Format("{0:0.0}")</text>);

It only happens when the data source I am binding to does not have any elements.
How do I prevent the NullReferenceException from occurring in such a case?

I am using 2012.1.214

Thank you,
Philip