private int getGaugeValue(Map<String, Gauge> gauges, String className, String suffix) {
    return (int) gauges.get(className + "." + suffix).getValue();
  }
Get the gauge value for the metric in {@link StorageManagerMetrics} for the given class and suffix.
@param gauges Map of gauge metrics to use
@param className the class to which the metric belongs to
@param suffix the suffix of the metric that distinguishes it from other metrics in the class.
@return the value of the counter.
ambry-store/src/test/java/com/github/ambry/store/StorageManagerTest.java