launch
Launches a coroutine in scope that calls sampleOnce and then waits interval, until the scope or the returned Job is cancelled. The first sample is taken immediately. The job never swallows cancellation.
Return
the Job of the sampling loop; cancel it to stop sampling.
Parameters
scope
scope that owns the sampling coroutine.
interval
delay between samples; must be positive.
Throws
if interval is not positive.