how to add a JRComponentElement by code ?

I know how to add elements by code, for example, to add a text element:

JRPrintPage jrPage      = new JRBasePrintPage();
txt = new JRBasePrintText(null);
jrPage.addElement(txt);

but how do I add a component element ? I want to add a barcode4j element, inspecting a designed report I found barcode4j is wrapped as a component inside a "JRBaseComponentElement" , but I don't know how to add manually