https://medium.com/@andrzejchm/presentation-model-and-passive-view-in-mvp-the-android-way-fdba56a35b1e

GoodPresentationModel.java

public class GoodPresentationModel implements Serializable {

    public static final Birthday TODAY = new Birthday();
    private List<User> users = Collections.emptyList();

    public void setUsers(List<User> users) {
        this.users = users;
    }

    public boolean shouldDisplayEmptyState() {
        return users.isEmpty();
    }

    public List<User> getAllUsers() {
        return Collections.unmodifiableList(users);
    }

    public List<User> hasAnyUserBirthdayToday() {
        for (User user : users) {
            if (isBirthdayToday(user.getBirthday())) {
                return true;
            }
        }
        return false;
    }

    public List<User> getUsersWithBirthday() {
        List<Users> result = new LinkedList<>();
        for (User user : users) {
            if (isBirthdayToday(user.getBirthday())) {
                result.add(user);
            }
        }
        return Collections.unmodifiableList(result);
    }

    private boolean isBirthdayToday(Birthday birthday) {
        return birthday.getMonth() == TODAY.getMonth() && birthday.getDay() == TODAY.getDay();
    }
}