public abstract void innerReceive(Properties properties);
@Test
    void testInnerReceive() {
        final Deque<Properties> q2 = new ArrayDeque<Properties>();
        PropertiesListener a = new PropertiesListener() {
            @Override
            public void innerReceive(Properties properties) {
                q2.offer(properties);
            }
        };
        Properties input = new Properties();
        input.put("foo", "bar");
        a.innerReceive(input);
        final Properties actual = q2.poll();
        assertEquals(1, actual.size());
        assertEquals("bar", actual.getProperty("foo"));
    }