public void addNumPersistentStores(Integer numPersistentStores) {
    addToMetricsMessage(GROUP_NAME_FOR_DIAGNOSTICS_MANAGER, CONTAINER_NUM_PERSISTENT_STORES_METRIC_NAME,
        numPersistentStores);
  }
Add the num stores with changelog parameter to the message.
@param numPersistentStores the parameter value.
samza-core/src/main/scala/org/apache/samza/diagnostics/DiagnosticsStreamMessage.java