tick = .Ticker~new(0.5 ,.message~new(.stdout, "SAY", "I", "knock, knock"))
call SysSleep 0.75                                           -- knock, knock
say "Ticker" tick~cancelled~?("cancelled", "not cancelled")  -- Ticker not cancelled
call SysSleep 0.5                                            -- knock, knock
tick~cancel
say "Ticker" tick~cancelled~?("cancelled", "not cancelled")  -- Ticker cancelled