### Question:
QueueCleanupCallback implements BooleanSupplier { @Override public boolean getAsBoolean() { queueManager.confirmReceipt(queueName, receiptHandle); return true; } QueueCleanupCallback(QueueManager queueManager, String queueName, String receiptHandle); @Override boolean getAsBoolean();  }### Answer:
@Test public void get_getCalled_queueMessageAcknowledged() { QueueManager queueManagerMock = createMock(QueueManager.class); queueManagerMock.confirmReceipt("foo", "foo_msg"); expectLastCall().once(); replay(queueManagerMock); QueueCleanupCallback callback = new QueueCleanupCallback(queueManagerMock, "foo", "foo_msg"); callback.getAsBoolean(); verify(queueManagerMock); }