Register a timer that expires after some delay and repeats some number of
times. At each expiry, will call the handler, passing the arg. To run a
timer forever, use 0 times. Returns a timer_id that is used to cancel the
timer in the future. Returns -1 if there was an error.

def timer(self, delay, times, handler, arg):
        """
        Register a timer that expires after some delay and repeats some number of
times. At each expiry, will call the handler, passing the arg. To run a
timer forever, use 0 times. Returns a timer_id that is used to cancel the
timer in the future. Returns -1 if there was an error.
        """
        return lib.zloop_timer(self._as_parameter_, delay, times, handler, arg)