code: public String hrefTemplate() {
          UriTemplateBuilder uriTemplateBuilder = UriTemplate.buildFromTemplate(hrefTemplate);
          if (!queryParams.isEmpty()) {
              uriTemplateBuilder = uriTemplateBuilder.query(
                      queryParams.keySet().toArray(new String[queryParams.keySet().size()]));
          }
          return uriTemplateBuilder.build().getTemplate();
      }
docs: Return the href template. It's empty unless the path is templated.
  
  @return hrefTemplate