=head3 unlink_marc_bundled_item

  $biblio->unlink_marc_bundled_item({ bundled_item => $item });

  $biblio->unlink_marc_bundled_item({ bundled_item => $itemnumber });

Remove the link to the child created by link_marc_bundled_item. Expects either the item object or itemnumber of the host to link to.

=cut

sub unlink_marc_bundled_item {

    my ( $self, $params ) = @_;

    my $bundled_item_itemnumber;

    if ( ref( $params->{bundled_item} ) eq 'Koha::Item' ) {

        $bundled_item_itemnumber = $params->{bundled_item}->itemnumber;

    } else {

        $bundled_item_itemnumber = $params->{bundled_item};

    }

    my $record       = $self->metadata->record;

    my $field_number = C4::Context->preference('marcflavour') eq 'MARC21' ? '774' : '462';

    my @fields       = $record->field($field_number);

    foreach my $field (@fields) {

        my $subfield_itemnumber = $field->subfield('9') // q{};

        if ( $bundled_item_itemnumber eq $subfield_itemnumber ) {

            $record->delete_field($field);

        }

    }

    C4::Biblio::ModBiblio( $record, $self->biblionumber );

}

        $item->biblio->unlink_marc_bundled_item( { bundled_item => $bundle_item } );