Tree Aggregates do not update when the model changes, however the footer does

Please take a look at the following plnkr. http://plnkr.co/edit/xrTwwyzYG3yy1RhCg1R0?p=preview

If you edit a balance value, the column footer aggregate automatically updates but the tree aggregate value does not.

Further investigation shows that the entity object is not updated but if I dig into the treeNode.aggregations array for the row, I can obtain the updated value.

The Complex tree tutorial does not cover this scenario, it would be be beneficial to show what helper methods to use to obtain these values.

Thanks for a great lib