code: @Override
      public String indexValue(String name, Object value) {
          if (value == null) {
              return null;
          } else if (value instanceof UUID) {
              UUID uuid = (UUID) value;
              return serialize(uuid);
          } else if (value instanceof String) {
              UUID uuid = UUID.fromString((String) value);
              return serialize(uuid);
          } else {
              throw new IllegalArgumentException();
          }
      }
docs: {@inheritDoc}