Change so if there are no traces you don't get NaN parallelism
Change so if there are no traces you don't get NaN parallelism

nh2/shake,ndmitchell/shake,ndmitchell/shake,nh2/shake,ndmitchell/shake,ndmitchell/shake,nh2/shake,nh2/shake,ndmitchell/shake,nh2/shake,ndmitchell/shake