This object has only one dispatch method.
This dispatch method totals various auxiliary slots of the elements.
When Inflow and Outflow for the Aggregate Reach are known, it is assumed that all interior reaches have dispatched and solved for all auxiliary slots.
The method then sums all these values (Diversion, Return Flow, and Local Inflow) and reports them in the appropriate total slot on the Aggregate Reach. If any value is NaN, the total does not include any contribution from that slot on that element.