protected FastJsonConfig locateConfigProvider(Class<?> type, MediaType mediaType) {
        if (providers != null) {
            ContextResolver<FastJsonConfig> resolver = providers.getContextResolver(FastJsonConfig.class, mediaType);
            if (resolver == null) {
                resolver = providers.getContextResolver(FastJsonConfig.class, null);
            }
            if (resolver != null) {
                return resolver.getContext(type);
            }
        }
        return fastJsonConfig;
    }
Helper method that is called if no config has been explicitly configured.
extension-jaxrs/extension-jaxrs-javax/src/main/java/com/alibaba/fastjson2/support/jaxrs/javax/FastJson2Provider.java