code: public Long getValue(Meter.Type meterType) {
          if (meterType == Meter.Type.DISTRIBUTION_SUMMARY) {
              return getDistributionSummaryValue();
          }
          if (meterType == Meter.Type.TIMER) {
              return getTimerValue();
          }
          return null;
      }
docs: Return the underlying value of the SLA in form suitable to apply to the given meter
  type.
  @param meterType the meter type
  @return the value or {@code null} if the value cannot be applied