docs: public static String findLowestTier(String[] tiers) {
      //if only 1 store then you don't need to find the lowest tier
      if (tiers.length == 1) {
        return tiers[0];
      }
  
      //we expect at least one tier
      if (tiers.length == 0) {
        throw new RuntimeException("No existing tier");
      }
  
      // We rely here on the alphabetical order matching the depth order so from highest to lowest we have
      // OnHeap, OffHeap, Disk, Clustered
      String lowestTier = tiers[0];
      for (int i = 1; i < tiers.length; i++) {
        if (tiers[i].compareTo(lowestTier) < 0) {
          lowestTier = tiers[i];
        }
      }
  
      return lowestTier;
    }