docs: public static int validateGeohashMaxLevels(Integer userMaxLevels, int defaultMaxLevels) {
          int maxLevels = userMaxLevels == null ? defaultMaxLevels : userMaxLevels;
          if (maxLevels < 1 || maxLevels > GeohashPrefixTree.getMaxLevelsPossible()) {
              throw new IndexException("max_levels must be in range [1, {}], but found {}",
                                       GeohashPrefixTree.getMaxLevelsPossible(),
                                       maxLevels);
          }
          return maxLevels;
      }