private static User randomUser() {
        String firstName = FIRST_NAMES[(int)(Math.random() * FIRST_NAMES.length)];
        String lastName = LAST_NAMES[(int)(Math.random() * LAST_NAMES.length)];
        return new User(firstName, lastName);
    }
@return A User with a random first and last name chosen from FIRST_NAMES and LAST_NAMES.
DataBindingDataBoundList/app/src/main/java/com/example/android/databoundlist/ButtonHandler.java