code: public double getPerformance(int evaluation) {
      if ((m_Metrics != null) && !m_Metrics.check(evaluation))
        return Double.NaN;
  
      if (!m_MetricValues.containsKey(evaluation))
        return Double.NaN;
  
      return m_MetricValues.get(evaluation);
    }
docs: returns the performance measure.
  
  @param evaluation	the type of evaluation to return
  @return 			the performance measure