code: public final double getStandardDeviation(final AbstractMeter meter) {
          checkIfMeterExists(meter);
          final AbstractUnivariateStatistic stdDev = new StandardDeviation();
          final CollectionDoubleCollection doubleColl = new CollectionDoubleCollection(this.meterResults.get(meter));
          return stdDev.evaluate(doubleColl.toArray(), 0, doubleColl.toArray().length);
      }
docs: Computes the standard deviation.
  
  @param meter the meter of the mean
  @return the standard deviation