@Override
public VisitResult visit(VisitContext context, UIComponent target) {
if (target instanceof AbstractPoint) {
AbstractPoint p = (AbstractPoint) target;
Object x = p.getX();
Object y = p.getY();
//the first point determine type of data model
if (model == null) {
if (x instanceof Number && y instanceof Number) {
model = new NumberChartDataModel(type);