code: public void onRemoveTab(final AjaxRequestTarget target, final T tab)
  	{
  		final int index = getTabs().indexOf(tab);
  		if (0 <= index)
  		{
  			onRemoveTab(target, index);
  		}
  	}
docs: On remove tab removes the given tab if it does exists.
  
  @param target
  the target
  @param tab
  the tab