code: public void userIdentifierInvalid(final String userId) {
  		this.addStatusMessage(
  				ProtocolConstants.StatusCodes.Create.User.USER_EXISTING,
  				"there is already a user with the identifier \""
  						+ userId
  						+ "\" existing. Please provide a valid user identifier.");
  	}
docs: add status message: user identifier invalid
  
  @param userId
  user identifier passed