public static void main(String[] args) throws IOException {
        JsonFactory surrogatePairFactory = JsonFactory.builder()
                .build();
        JsonFactory utf8Factory = JsonFactory.builder()
                .enable(JsonWriteFeature.COMBINE_UNICODE_SURROGATES_IN_UTF8)
                .build();
        JsonFactory utf8FactoryWithCharacterEscapes = new JsonFactoryBuilder()
                .characterEscapes(JsonpCharacterEscapes.instance())
                .enable(JsonWriteFeature.COMBINE_UNICODE_SURROGATES_IN_UTF8)
                .build();
        System.out.println(writeEmoji(surrogatePairFactory));
        System.out.println(writeEmoji(utf8Factory));
        System.out.println(writeEmoji(utf8FactoryWithCharacterEscapes));
    }

    private static String writeEmoji(JsonFactory f) throws IOException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try (JsonGenerator gen = f.createGenerator(out)) {
            gen.writeStartObject();
            // 0x1F60A - emoji
            gen.writeStringField("test_emoji", new String(Character.toChars(0x1F60A)));
            gen.writeEndObject();
        }
        return out.toString(StandardCharsets.UTF_8);
    }