code: protected boolean startInputGroupForAddOn(ResponseWriter rw, boolean hasPrependingAddOn, boolean hasAppendingAddOn,
  			SelectOneMenu menu) throws IOException {
  		final boolean hasAddon = hasAppendingAddOn || hasPrependingAddOn;
  		if (hasAddon) {
  			rw.startElement("div", menu);
  			rw.writeAttribute("class", "input-group", "class");
  		}
  		return hasAddon;
  	}
docs: Starts the input field group (if needed to display a component seamlessly in
  front of or behind the input field). This method is protected in order to
  allow third-party frameworks to derive from it.
  
  @param hasAppendingAddOn
  
  @param rw
  the response writer
  @param hasPrependingAddOn
  @return true if there is an add-on in front of or behind the input field
  @throws IOException
  may be thrown by the response writer