public static JvmGcMonitorMetrics getInstance() {
    return JvmGcMetricsHolder.INSTANCE;
  }
The user can provide an instance of a class implementing this interface when initializing a
GCTimeMonitor to receive alerts when GC time percentage exceeds the specified threshold.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/service/metric/JvmGcMonitorMetrics.java