docs: public Map<String, String> getAdditionalAuthorizationAttributes(String authoritiesJson) {
          if (StringUtils.hasLength(authoritiesJson)) {
              try {
                  Map<String, Object> authorities = JsonUtils.readValue(authoritiesJson, new TypeReference<Map<String, Object>>() {});
                  Object az_attr = authorities.get("az_attr");
                  if(az_attr == null)
                      return null;
                  // validate az_attr content with Map<String, String>>
                  Map<String, String> additionalAuthorizationAttributes =
                      JsonUtils.readValue(JsonUtils.writeValueAsBytes(az_attr), new TypeReference<Map<String, String>>() {});
  
                  return additionalAuthorizationAttributes;
              } catch (Throwable t) {
                  logger.error("Unable to read additionalAuthorizationAttributes", t);
              }
          }
  
          return null;
      }