### Question:
ProcessEngineEventsAggregator extends BaseCommandContextEventsAggregator<CloudRuntimeEvent<?,?>, MessageProducerCommandContextCloseListener> { @Override protected String getAttributeKey() { return MessageProducerCommandContextCloseListener.PROCESS_ENGINE_EVENTS; } ProcessEngineEventsAggregator(MessageProducerCommandContextCloseListener closeListener); @Override void add(CloudRuntimeEvent<?, ?> element);  }### Answer:
@Test public void getAttributeKeyShouldReturnProcessEngineEvents() { String attributeKey = eventsAggregator.getAttributeKey(); assertThat(attributeKey).isEqualTo(MessageProducerCommandContextCloseListener.PROCESS_ENGINE_EVENTS); }