code: public long maxRate() {
          long max = (samples.isEmpty() ? 0L : samples.get(0).rate());
          for (Sample s : samples) {
              max = Math.max(max, s.rate());
          }
          return max;
      }
docs: Returns the maximum of the message rates in the SampleGroup.
  
  @return the maximum of the message rates in the SampleGroup