public User connect(List<User> users) {

        // User input.
        List<String> words = this.getParser().getInput();

        if (words.size() > 1) {

            for (User u : users) {

                // If the user is in the list, the connection succeed.
                if (u.getFirstName().equalsIgnoreCase(words.get(0))
                        && u.getLastName().equalsIgnoreCase(words.get(1))) {

                    return u;
                }
            }
        }

        return null;
    }