@Override
	public int registerUser(UserRequest request) {
		int result = -1;
		
		User unvalidatedUser = new User(request.getUsername(), request.getPassword());
		if(users.indexOf(unvalidatedUser) == -1 && request.validatePreConditions()) {
			users.add(unvalidatedUser);
			result = users.indexOf(unvalidatedUser);
		}
		
		System.out.println("User registration return code: " + result);
		
		return result;
	}