code: @Override
      protected Collection<Object> elementsOf(Object facetValue) {
          int length = Array.getLength(facetValue);
          List<Object> list = new ArrayList<>(length);
          for (int i = 0; i < length; i++) {
              list.add(Array.get(facetValue, i));
          }
          return list;
      }
docs: ----------------------------------------------------------------------------------------------------------------------