I know I wrote this line.. it's hard to read and understand at a glance.  What it's trying to say is, disable_and_reenable_metric_unless_it_never_enables_itself .... That we want to enforce the metric to be enabled only by its internal rules, regardless of its current state. But, because we've set rcov to never enable itself, don't disable it; leave its state of enabledness alone.  It's a smell of something wrong, for one thing, and the other, that I think it may also be a need in testing creeping into the implementation-- being able to 'reset' the configuration.  Needs some thought.