code: @Override
      public Map<Long, Double> mapping(Map<Long, Double> originalDatapoints) {
          Map<Long, Double> sortedDatapoints = new TreeMap<>();
          Double prevSum = 0.0;
  
          sortedDatapoints.putAll(originalDatapoints);
          for (Entry<Long, Double> entry : sortedDatapoints.entrySet()) {
              prevSum += entry.getValue();
              sortedDatapoints.put(entry.getKey(), prevSum);
          }
          return sortedDatapoints;
      }
docs: ~ Methods **************************************************************************************************************************************