code: public void onNewTab(final AjaxRequestTarget target, final T tab, final int index)
  	{
  		if ((index < 0) || (index >= getTabs().size()))
  		{
  			throw new IndexOutOfBoundsException();
  		}
  		getTabs().add(index, tab);
  		setSelectedTab(index);
  		target.add(this);
  	}
docs: On new tab.
  
  @param target
  the target
  @param tab
  the tab
  @param index
  the index