'Set timers that timers that fires in succession with the sepecified
interval.'

def set_timers(self):

    self.timer_stack = list()
    for i in range(self.NUM_TIMERS, 0, (-1)):
        deadline = (i * self.TIMER_INTERVAL)
        self.ioloop.add_timeout(deadline, partial(self.on_timer, i))
        self.timer_stack.append(i)
