Dealinc function income_prorate() clarification

Hi,

the dealinc process has a function named income_prorate(), being called after the standard income calculation right before exiting the process() function.
I do not see any utility from that function that basically update the DEAL_ACTUALS_ITEM_LOC.actual_income
with the same values, as calculated before.
So my question is, if this is useful what's the functional goal of it ?
Or the original goal of it has been deprecated and now it does not makes any sense - and so it should be removed, since it seems to basically be wasting time and resources unnecessarily.

Thanks
Best Regards