Sorting doesn't work with cellFilter and customTreeAggregationFinalizerFn for 'number'

http://ui-grid.info/docs/#/tutorial/209_grouping

In the tutorials there is an example for doing a cellFilter for 'Balance' that will still work for aggregation. It's not apparent from the provided data (since they are all in the thousand range), but sorting doesn't work correctly for that column. It sorts it in lexicographical order instead of numerical order. I've tried with the number filter in angular as well.

I tried adding the type: 'number', which makes the sorting work, but breaks the aggregation total.