class virtualUse['a]
time :?t0:Cf_tai64n.t -> float ->
object
..end
inherit time ?start interval
to derive an I/O event that is
serviced after the system clock reaches a specific time and at constrant
intervals thereafter. If ?start
is not provided, then the start time
is immediately after the first interval.val mutable epoch_ : Cf_tai64n.t