assertContains(
                problems.messages.get(0),
                "'proxies.proxy.id' must be unique" + " but found duplicate proxy with id " + id);
    }

    @Test
    void testValidateProxy() throws Exception {
        Settings settings = new Settings();
        Proxy proxy1 = new Proxy();
        settings.addProxy(proxy1);

        SimpleProblemCollector problems = new SimpleProblemCollector();