@Override
    protected String getMessageId(Exchange exchange) {
        return exchange.getIn().getHeader(CAMEL_IRON_MQ_MESSAGE_ID, String.class);
    }
@Test
    public void testGetMessageId() {
        String messageId = "abcd";
        Exchange exchange = Mockito.mock(Exchange.class);
        Message message = Mockito.mock(Message.class);

        Mockito.when(exchange.getIn()).thenReturn(message);
        Mockito.when(message.getHeader(IronmqSpanDecorator.CAMEL_IRON_MQ_MESSAGE_ID, String.class)).thenReturn(messageId);

        AbstractMessagingSpanDecorator decorator = new IronmqSpanDecorator();

        assertEquals(messageId, decorator.getMessageId(exchange));
    }