code: @Override
      public final Health health() {
          logger.debug("Health");
          final Builder builder = Health.up();
          logger.debug("    " + appInfo.getVersion());
          builder.withDetail("version", appInfo.getVersion());
          final List<Map<String, Object>> details = loader.details();
          logger.debug("    " + details.size() + " datasets");
          builder.withDetail("datasets", details);
          builder.up();
          return builder.build();
      }
docs: {@inheritDoc}