@Override
public int compare(Hymn a, Hymn b) {
return (int) (a.getId() - b.getId());
}
@Override
public int compare(Hymn a, Hymn b) {
return a.getAuthor().compareTo(b.getAuthor());
}
@Override
public int compare(Hymn a, Hymn b) {
return a.getTitle().compareTo(b.getTitle());
}