docs: long getYearDifference(long minuendInstant, long subtrahendInstant) {
          // optimsed implementation of getDifference, due to fixed months
          int minuendYear = getYear(minuendInstant);
          int subtrahendYear = getYear(subtrahendInstant);
  
          // Inlined remainder method to avoid duplicate calls to get.
          long minuendRem = minuendInstant - getYearMillis(minuendYear);
          long subtrahendRem = subtrahendInstant - getYearMillis(subtrahendYear);
  
          int difference = minuendYear - subtrahendYear;
          if (minuendRem < subtrahendRem) {
              difference--;
          }
          return difference;
      }