### Question:
ItemSourceAppender implements ItemAppender<LogEvent> { @Override public void start() { batchDelivery.start(); state = State.STARTED; LOG.debug("{} started", getClass().getSimpleName()); } ItemSourceAppender(BatchDelivery batchDelivery, Function<LogEvent, ItemSource> serializer); @Override final void append(String formattedIndexName, LogEvent event); @Override void start(); @Override void stop(); @Override boolean isStarted(); @Override boolean isStopped();  }### Answer:
@Test public void lifecycleStartStartsBatchDelivery() { BatchDelivery batchDelivery = mock(BatchDelivery.class); ItemAppender itemAppender = new ItemSourceAppender(batchDelivery, logEvent -> null); itemAppender.start(); verify(batchDelivery).start(); }