code: public Feature nextFeature() {
  	Feature f = null;
      
  	if (hasNextSFeature()) {
  	    f = nextSFeature();
  	} else if (hasNextEFeature()) {
  	    f = nextEFeature();
  	} else {
  	    // do nothing
  	}
  	
  	return f;
      }
docs: Next feature.
  
  @return the feature