code: private void updateStats(InstanceContentEvent event) {
                  Instance inst = event.getInstance();
  		this.model.trainOnInstance(inst);
  		this.instancesCount++;
  		if (this.changeDetector != null) {
  				boolean correctlyClassifies = this.correctlyClassifies(inst);
  				double oldEstimation = this.changeDetector.getEstimation();
  				this.changeDetector.input(correctlyClassifies ? 0 : 1);
  				if (this.changeDetector.getChange() && this.changeDetector.getEstimation() > oldEstimation) {
  						//Start a new classifier
  						this.model.resetLearning();
  						this.changeDetector.resetLearning();
  				}
  		}
  	}
docs: Update stats.
  
  @param event the event