code: private void updateJobStats(Phase phase, ProcessingRates oldRates, 
        ProcessingRates newRates) {
      DataStatistics stats = job.getRunningTaskStatistics(phase);
      stats.updateStatistics(oldRates.getRate(phase), newRates.getRate(phase));
    }
docs: Helper function that updates the processing rates stats for this job. Only
  updates the rate in the corresponding phase.
  @param phase
  @param oldRates
  @param newRates