### Question:
Tracker implements TrackerMBean { public void removeAllMetricNames() { metricNames.clear(); log.info("[TRACKER] All metric names removed."); } 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 testRemoveAllMetricNames() { tracker.addMetricName("metricName"); tracker.addMetricName("anotherMetricNom"); assertTrue("metricName not being logged",tracker.doesMessageContainMetricNames("Track.this.metricName")); assertTrue("anotherMetricNom not being logged",tracker.doesMessageContainMetricNames("Track.this.anotherMetricNom")); assertFalse("randomMetricNameNom should not be logged", tracker.doesMessageContainMetricNames("Track.this.randomMetricNameNom")); tracker.removeAllMetricNames(); assertTrue("Everything should be logged", tracker.doesMessageContainMetricNames("Track.this.metricName")); assertTrue("Everything should be logged", tracker.doesMessageContainMetricNames("Track.this.anotherMetricNom")); assertTrue("Everything should be logged", tracker.doesMessageContainMetricNames("Track.this.randomMetricNameNom")); }