Add some more strictness to Pool, useful to ensure no space leaks
Add some more strictness to Pool, useful to ensure no space leaks

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