This function will return a number corresponding to the system time and remain stable until a given number of seconds have elapsed, after which it will update to the current time. This makes it useful as a way to timeout and invalidate a memoised cache after a certain period of time.
timeout(seconds, current = as.numeric(Sys.time()))
Number of seconds after which to timeout.
The current time as a numeric.
A numeric that will remain constant until the seconds have elapsed.
#>  0.4321713 0.7064338