public List<AmbariEvent> getAmbariEventInstances(Class<? extends AmbariEvent> clazz){
    if (!m_receivedAmbariEvents.containsKey(clazz)) {
      return Collections.emptyList();
    }

    return m_receivedAmbariEvents.get(clazz);
  }
Get the instances

@param clazz
@return
ambari-server/src/test/java/org/apache/ambari/server/events/MockEventListener.java