onlyOnce sync.Once
}

func (f *leaderMetricsFactory) setProvider(mp MetricsProvider) {
	f.onlyOnce.Do(func() {
		f.metricsProvider = mp
	})
}

func (f *leaderMetricsFactory) newLeaderMetrics() leaderMetricsAdapter {
	mp := f.metricsProvider
	if mp == (noopMetricsProvider{}) {
		return noMetrics{}
	}
	return &defaultLeaderMetrics{
		leader: mp.NewLeaderMetric(),
	}
}