@Override
    public Iterator<Map.Entry<String, Object>> iterator() {
        return map.entrySet().iterator();
    }
@Test
    public void noProperties() {
        CamelMessagingHeadersExtractAdapter adapter = new CamelMessagingHeadersExtractAdapter(map, true);
        Iterator<Map.Entry<String, Object>> iterator = adapter.iterator();
        assertFalse(iterator.hasNext());
    }