code: function decodeString (string) {
  	if (string === values.EMPTY) {
  		return "";
  	} else if (string === values.NULL) {
  		return null;
  	} else {
  		return decodeURIComponent(
  			string.replace(/\+/g,"%20"));
  	}
  }
docs: Decodes a string according to the ARI protocol.
  
  @param {String} string input
  @return {String} output
  @private