*/
@Override
public void encodeBegin(FacesContext context, UIComponent component) throws IOException {
super.encodeBegin(context, component);
AbstractChart chart = (AbstractChart) component;
VisitChart visitCallback = new VisitChart(chart);
//copy attributes to parent tag and process data
chart.visitTree(VisitContext.createVisitContext(FacesContext.getCurrentInstance()), visitCallback);
//store data to parent tag
component.getAttributes().put("data", visitCallback.getData());
if(!visitCallback.isDataEmpty()){