public void classiferQuantile() {
SimpleFeatureCollection collection = null;
SimpleFeature feature = null;
// classiferQuantile start
FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
Function classify = ff.function("Quantile", ff.property("zone"), ff.literal(2));
// Zones assigned by a municipal board do not have an intrinsic numerical
// meaning making them suitable for display using:
// - qualitative palette where each zone would have the same visual impact
Classifier groups = (Classifier) classify.evaluate(collection);