code: protected Pair[] getHalf(boolean bestHalf){
      	
      	Pair[] newEnsembleWeights = new Pair[getNbAdaptiveClassifiers()];
      	System.arraycopy(ensembleWeights, 0, newEnsembleWeights, 0, newEnsembleWeights.length);
      	
      	if (bestHalf)
      		Arrays.sort(newEnsembleWeights,Collections.reverseOrder());
      	else
      		Arrays.sort(newEnsembleWeights);
      		
      	Pair[] result = new Pair[(int)Math.floor(newEnsembleWeights.length/2)];
      	System.arraycopy(newEnsembleWeights, 0, result, 0, result.length);
      	
      	return result;
      }
docs: Returns the best (or worst) half of classifiers in the adaptive ensemble.
  The best classifiers are used to compute the stability index in ADACC. The worst
  classifiers are returned in order to select a classifier for deletion.
  @param bestHalf boolean value set to true (false) if we want to return
  the best (worst) half of adaptive classifiers.
  @param horizon
  @return an array containing the weight values of the corresponding classifiers
  and their indexes in the ensemble.