1True 2task start 3True 4main sleep 5task cancel 6task start 7True 8True 9True 10True 11main sleep 12task cancel 13main wait 14main got CancelledError 15task start 16task done 17False 18---- 19task 2 20task start 21main cancel 22main sleep 23task cancel 24task 2 cancel 25---- 26task 2 27task start 28main cancel 29main sleep 30task cancel 31task 2 done 32