The migration plan alluded to in DMTN-098, and researched in
DM-16503, involved creating separate Gen 2 and Gen 3 MetricTasks. This plan was motivated by the assumption that metrics would be in wide use by the time of the migration, making writing a class adapter for each and every metric impractical. However, MetricTask has seen limited uptake, making the careful approach unnecessary.
The new plan is to follow the process the Middleware group has been using, and retrofit Gen 3 functionality onto MetricTask directly. The only loose end is the current use of gen2tasks.MetricTask.
Move gen2tasks.MetricTask to tasks.MetricTask, keeping the old name as a deprecated alias (much as we did when we created the new geom package from afw.geom). Update known MetricTasks to use the new name immediately.