code: func RegisterVolumeSchedulingMetrics() {
  	prometheus.MustRegister(VolumeBindingRequestSchedulerBinderCache)
  	prometheus.MustRegister(VolumeSchedulingStageLatency)
  	prometheus.MustRegister(VolumeSchedulingStageFailed)
  }
docs: // RegisterVolumeSchedulingMetrics is used for scheduler, because the volume binding cache is a library
  // used by scheduler process.