code: public static String getString(String key, Object... params) {
  		String message = getStringSafely(key);
  		if (params != null && params.length > 0) {
  			return MessageFormat.format(message, params);
  		} else {
  			return message;
  		}
  	}
docs: Applies the message parameters and returns the message
  from one of the message bundles.
  
  @param key property key
  @param params message parameters to be used in message's place holders
  @return Resource value or place-holder error String