$self->{_items} ||= Koha::Items->search( { biblionumber => $self->biblionumber() } );

    my $items_rs = $self->_result->items;

    return wantarray ? $self->{_items}->as_list : $self->{_items};

    return

        wantarray

        ? Koha::Items->_new_from_dbic($items_rs)->as_list

        : Koha::Items->_new_from_dbic($items_rs);