@Override
    public void close() {
        if (ch.isOpen()) {
            ch.close();
        }
    }
@Test
    public void testNonCachedResolve() throws Exception {
        DnsNameResolver resolver = newNonCachedResolver(ResolvedAddressTypes.IPV4_ONLY).build();
        try {
            testResolve0(resolver, EXCLUSIONS_RESOLVE_A, null);
        } finally {
            resolver.close();
        }
    }