stagerunner.remember for always switching off intermediate progress, e.g., when running jobs on a machine that never needs replay capability.stageRunner, stageRunnerNode, and treeSkeleton reference classes to use R6 classes, in preparation for public release of the package.is_pre_stagerunner helper function that returns TRUE or FALSE according as an object can be transformed into a stageRunner.tracked_environment object as the context to a stageRunner will result in much smarter memory management of environment changes as you run its stages (objectdiff uses clever patching functions to record only changes to an environment as it is being modified; without this logic, a stageRunner has to copy an environment in full on each executed stage, which is especially expensive if you are manipulating large data sets).