### Question:
Tracker implements TrackerMBean { public void trackDelayedMetricsTenant(String tenantid, final List<Metric> delayedMetrics) { if (isTrackingDelayedMetrics) { String logMessage = String.format("[TRACKER][DELAYED METRIC] Tenant sending delayed metrics %s", tenantid); log.info(logMessage); double delayedMinutes; long nowMillis = System.currentTimeMillis(); for (Metric metric : delayedMetrics) { delayedMinutes = (double)(nowMillis - metric.getCollectionTime()) / 1000 / 60; logMessage = String.format("[TRACKER][DELAYED METRIC] %s has collectionTime %s which is delayed by %.2f minutes", metric.getLocator().toString(), dateFormatter.format(new Date(metric.getCollectionTime())), delayedMinutes); log.info(logMessage); } } } private  Tracker(); static Tracker getInstance(); synchronized void register(); void addTenant(String tenantId); void removeTenant(String tenantId); void removeAllTenants(); Set getTenants(); void addMetricName(String metricName); void removeMetricName(String metricName); void removeAllMetricNames(); Set<String> getMetricNames(); void setIsTrackingDelayedMetrics(); void resetIsTrackingDelayedMetrics(); boolean getIsTrackingDelayedMetrics(); boolean isTracking(String tenantId); boolean doesMessageContainMetricNames(String logmessage); void track(HttpRequest request); void trackResponse(HttpRequest request, FullHttpResponse response); void trackDelayedMetricsTenant(String tenantid, final List<Metric> delayedMetrics); void trackDelayedAggregatedMetricsTenant(String tenantId, long collectionTimeMs, long delayTimeMs, List<String> delayedMetricNames); static final String trackerName; }### Answer:
@Test public void testTrackDelayedMetricsTenant() { tracker.setIsTrackingDelayedMetrics(); tracker.trackDelayedMetricsTenant(tenantId, delayedMetrics); verify(loggerMock, atLeastOnce()).info("[TRACKER] Tracking delayed metrics started"); verify(loggerMock, atLeastOnce()).info("[TRACKER][DELAYED METRIC] Tenant sending delayed metrics " + tenantId); verify(loggerMock, atLeastOnce()).info(contains("[TRACKER][DELAYED METRIC] " + tenantId + ".delayed.metric1 has collectionTime 2016-01-01 00:00:00 which is delayed")); verify(loggerMock, atLeastOnce()).info(contains("[TRACKER][DELAYED METRIC] " + tenantId + ".delayed.metric2 has collectionTime 2016-01-01 00:00:00 which is delayed")); }