private List<Notification> captureAllNotifications(int count) {
    ArgumentCaptor<Notification> captor = ArgumentCaptor.forClass(Notification.class);
    verify(notificationListener, timeout(TIMEOUT).times(count)).handleNotification(captor.capture(),
        isNull());
    return captor.getAllValues();
  }
Fails due to GEODE-5923: JMX manager only receives local Alerts at the default AlertLevel

<p>
The JMX manager's local AlertListener for itself remains stuck at {@code SEVERE} even after
invoking {@link DistributedSystemMXBean#changeAlertLevel(String)}.
geode-core/src/distributedTest/java/org/apache/geode/management/DistributedSystemMXBeanWithAlertsDistributedTest.java