How to use

isAsync

method

in

org.apache.wicket.markup.head.JavaScriptUrlReferenceHeaderItem

@Override
public void render(Response response)
{
  internalRenderJavaScriptReference(response,
    UrlUtils.rewriteToContextRelative(getUrl(), RequestCycle.get()), getId(), isDefer(),
    getCharset(), getCondition(), isAsync());
}

@Override
public void render(Response response)
{
  internalRenderJavaScriptReference(response,
    UrlUtils.rewriteToContextRelative(getUrl(), RequestCycle.get()), getId(), isDefer(),
    getCharset(), getCondition(), isAsync());
}