code: func Register() {
  	// Register the metrics.
  	registerMetrics.Do(func() {
  		prometheus.MustRegister(cacheHitCounter)
  		prometheus.MustRegister(cacheMissCounter)
  		prometheus.MustRegister(cacheEntryCounter)
  		prometheus.MustRegister(cacheAddLatency)
  		prometheus.MustRegister(cacheGetLatency)
  		prometheus.MustRegister(etcdRequestLatency)
  		prometheus.MustRegister(objectCounts)
  
  		// TODO(danielqsj): Remove the following metrics, they are deprecated
  		prometheus.MustRegister(deprecatedCacheHitCounter)
  		prometheus.MustRegister(deprecatedCacheMissCounter)
  		prometheus.MustRegister(deprecatedCacheEntryCounter)
  		prometheus.MustRegister(deprecatedCacheAddLatency)
  		prometheus.MustRegister(deprecatedCacheGetLatency)
  		prometheus.MustRegister(deprecatedEtcdRequestLatenciesSummary)
  	})
  }
docs: // Register all metrics.