code: protected String loadCacheBust(Scriptable cfg) {
  		String result = null;
  		Object value = cfg.get(CACHEBUST_CONFIGPARAM, cfg);
  		if (value != Scriptable.NOT_FOUND && value != Undefined.instance) {
  			result = toString(value);
  		}
  		return result;
  
  	}
docs: Initializes and returns the string specified by the {@code cacheBust}
  property in the server-side config JavaScript.
  
  @param cfg
  The parsed config JavaScript as a properties map
  @return the {@code cacheBust} property value