code: func RecordVolumeOperationMetric(pluginName, opName string, timeTaken float64, err error) {
  	if pluginName == "" {
  		pluginName = "N/A"
  	}
  	if err != nil {
  		volumeOperationErrorsMetric.WithLabelValues(pluginName, opName).Inc()
  		return
  	}
  	volumeOperationMetric.WithLabelValues(pluginName, opName).Observe(timeTaken)
  }
docs: // RecordVolumeOperationMetric records the latency and errors of volume operations.