@Override
  public boolean isAlertDefinitionCreated(StatAlertDefinition alertDefinition) {
    /*
     * Need to maintain a map of stat against the StatAlertDefinitions. check in that map whether
     * the alert definition is there for the given alert
     *
     * TODO: optimize to use Map.containsKey - DONE
     */
    synchronized (ALERT_DEFINITIONS) {
      return ALERT_DEFINITIONS.containsKey(alertDefinition.getId());
    }
  }
Convenience method to check whether an alert definition is created.

@param alertDefinition alert definition to check whether already created
@return true if the alert definition is already created, false otherwise
@since GemFire 5.7
geode-core/src/main/java/org/apache/geode/admin/jmx/internal/AdminDistributedSystemJmxImpl.java