@Override
    protected Pair<String, ProtocolNegotiatorBuilder> defaultBuilderPair() {
        return Pair.with(TYPE_PROPERTY_KEY, new SdkDefaultTlsProtocolNegotiatorBuilder());
    }
@Test
    void testDefaultBuilderPair() {
        Pair<String, ProtocolNegotiatorBuilder> defaultPair = SdkProtocolNegotiatorBuilderSingleton.getSingleton().defaultBuilderPair();
        assertNotNull(defaultPair);
        assertEquals(SdkProtocolNegotiatorBuilderSingleton.TYPE_PROPERTY_KEY, defaultPair.getFirst());
        assertNotNull(defaultPair.getSecond());
    }