code: public static List<Integer> getOriginalIndexes(int samplingLevel)
      {
          List<Integer> originalIndexes = originalIndexCache.get(samplingLevel);
          if (originalIndexes != null)
              return originalIndexes;
  
          List<Integer> pattern = getSamplingPattern(BASE_SAMPLING_LEVEL).subList(0, BASE_SAMPLING_LEVEL - samplingLevel);
          originalIndexes = new ArrayList<>(samplingLevel);
          for (int j = 0; j < BASE_SAMPLING_LEVEL; j++)
          {
              if (!pattern.contains(j))
                  originalIndexes.add(j);
          }
  
          originalIndexCache.put(samplingLevel, originalIndexes);
          return originalIndexes;
      }
docs: Returns a list that can be used to translate current index summary indexes to their original index before
  downsampling.  (This repeats every `samplingLevel`, so that's how many entries we return.)
  
  For example, if [0, 64] is returned, the current index summary entry at index 0 was originally
  at index 0, and the current index 1 was originally at index 64.
  
  @param samplingLevel the current sampling level for the index summary
  
  @return a list of original indexes for current summary entries