code: public WTab addTab(final WComponent content, final WDecoratedLabel label, final TabMode mode) {
  		return addTab(new WTab(content, label, mode, (char) 0));
  	}
docs: Adds a tab to the tab set.
  
  @param content the tab set content.
  @param label the tab's label, which can contain rich content (images or other components).
  @param mode the tab mode.
  @return the tab which was added to the tab set.