func (r *ewmaRate) rate() float64 {
	r.mutex.Lock()
	defer r.mutex.Unlock()
	return r.lastRate
}
func (r *ewmaRate) rate() float64 {
	r.mutex.Lock()
	defer r.mutex.Unlock()
	return r.lastRate
}
func ( r * ewmaRate ) rate ( ) float64 { r . mutex . Lock ( ) defer r . mutex . Unlock ( ) return r . lastRate }
// rate returns the per-second rate.
rate returns the per - second rate .