docs: public ServiceCall<Classifiers> listClassifiers(ListClassifiersOptions listClassifiersOptions) {
      String[] pathSegments = { "v3/classifiers" };
      RequestBuilder builder = RequestBuilder.get(RequestBuilder.constructHttpUrl(getEndPoint(), pathSegments));
      builder.query("version", versionDate);
      Map<String, String> sdkHeaders = SdkCommon.getSdkHeaders("watson_vision_combined", "v3", "listClassifiers");
      for (Entry<String, String> header : sdkHeaders.entrySet()) {
        builder.header(header.getKey(), header.getValue());
      }
      builder.header("Accept", "application/json");
      if (listClassifiersOptions != null) {
        if (listClassifiersOptions.verbose() != null) {
          builder.query("verbose", String.valueOf(listClassifiersOptions.verbose()));
        }
      }
      return createServiceCall(builder.build(), ResponseConverterUtils.getObject(Classifiers.class));
    }