public void diff(final Configuration rhs, final Configuration included, final Configuration excluded) {
        included.peers = new ArrayList<>(this.peers);
        included.peers.removeAll(rhs.peers);
        excluded.peers = new ArrayList<>(rhs.peers);
        excluded.peers.removeAll(this.peers);
    }
@Test
    public void testDiff() {
        final Configuration conf1 = JRaftUtils.getConfiguration("localhost:8081,localhost:8082,localhost:8083");
        final Configuration conf2 = JRaftUtils
            .getConfiguration("localhost:8081,localhost:8083,localhost:8085,localhost:8086");
        final Configuration included = new Configuration();
        final Configuration excluded = new Configuration();
        conf1.diff(conf2, included, excluded);
        assertEquals("localhost:8082", included.toString());
        assertEquals("localhost:8085,localhost:8086", excluded.toString());
    }