If true, the Timeout object will keep the event-loop active.

Returns

{boolean}

When called, requests that the event-loop not exit so long as the Timeout is active.

By default, all Timeout objects are "ref'ed", making it normally unnecessary to call timeout.ref() unless timeout.unref() had been called previously.

Sets the timer's start time to the current time, and reschedules the timer to call its callback at the previously specified duration adjusted to the current time.

Using this on a timer that has already called its callback will reactivate the timer.

When called, the active Timeout object will not require the event-loop to remain active.
If there is no other activity keeping the event-loop running, the process may exit before the Timeout object's callback is invoked.