code: @Override
  	public void renderHead(Component component, IHeaderResponse response)
  	{
  		super.renderHead(component, response);
  
  		JsStatement statement = statement();
  		if (statement != null)
  		{
  			String statementString = statement.render().toString();
  			if (!Strings.isEmpty(statementString))
  			{
  				response.render(OnDomReadyHeaderItem.forScript(statementString));
  			}
  		}
  	}
docs: <p>
  Since wicket 6.0 {@link #statement()} is no longer needed, nearly all of WiQuery
  core's inner workings have been ported to Wicket 6.0. Use
  {@link #renderHead(Component, IHeaderResponse)} to render your statement.
  </p>
  <p>
  For backward compatibility we render the output of this function in an
  {@link OnDomReadyHeaderItem} if it is not empty. For your convenience this abstract
  class returns null so that nothing is rendered.
  <p>