relay_timer_pool.go
func (rt *relayTimer) Release() {
	rt.verifyNotReleased()
	if rt.active {
		panic("only stopped or completed timers can be released")
	}
	rt.released = true
	rt.pool.Put(rt)
}
func (rt *relayTimer) Release() {
	rt.verifyNotReleased()
	if rt.active {
		panic("only stopped or completed timers can be released")
	}
	rt.released = true
	rt.pool.Put(rt)
}
// Release releases a timer back to the timer pool. The timer MUST have run or be
// stopped before Release is called.