code: public static String buildRegisteredServiceCacheKey(final SamlRegisteredService service) {
          val key = service.getMetadataLocation();
          LOGGER.trace("Determined cache key for service [{}] as [{}]", service.getName(), key);
          val hashedKey = DigestUtils.sha512(key);
          LOGGER.trace("Hashed service cache key as [{}]", hashedKey);
          return hashedKey;
      }
docs: Build registered service cache key string.
  
  @param service the service
  @return the string