docs: private void validateFilter(Filter filter) throws IllegalArgumentException {
      switch (filter.getFilterTypeCase()) {
        case COMPOSITE_FILTER:
          for (Filter subFilter : filter.getCompositeFilter().getFiltersList()) {
            validateFilter(subFilter);
          }
          break;
        case PROPERTY_FILTER:
          if (UNSUPPORTED_OPERATORS.contains(filter.getPropertyFilter().getOp())) {
            throw new IllegalArgumentException("Query cannot have any inequality filters.");
          }
          break;
        default:
          throw new IllegalArgumentException(
              "Unsupported filter type: " + filter.getFilterTypeCase());
      }
    }