Find all objects related to ``objs`` that should also be deleted. ``objs``
    must be a homogeneous iterable of objects (e.g. a QuerySet).
    Returns a nested list of strings suitable for display in the
    template with the ``unordered_list`` filter.

def get_deleted_objects(objs, opts, user, admin_site, using):
    """
    Find all objects related to ``objs`` that should also be deleted. ``objs``
    must be a homogeneous iterable of objects (e.g. a QuerySet).
    Returns a nested list of strings suitable for display in the
    template with the ``unordered_list`` filter.
    """
    # --- begin patch ---
    collector = PolymorphicAwareNestedObjects(using=using)
    # --- end patch ---
    collector.collect(objs)
    perms_needed = set()

    def format_callback(obj):
        has_admin = obj.__class__ in admin_site._registry
        opts = obj._meta

        no_edit_link = '%s: %s' % (capfirst(opts.verbose_name),
                                   force_text(obj))

        if has_admin:
            try:
                admin_url = reverse('%s:%s_%s_change'
                                    % (admin_site.name,
                                       opts.app_label,
                                       opts.model_name),
                                    None, (quote(obj._get_pk_val()),))
            except NoReverseMatch:
                # Change url doesn't exist -- don't display link to edit
                return no_edit_link

            p = '%s.%s' % (opts.app_label,
                           get_permission_codename('delete', opts))
            if not user.has_perm(p):
                perms_needed.add(opts.verbose_name)
            # Display a link to the admin page.
            return format_html('{}: <a href="{}">{}</a>',
                               capfirst(opts.verbose_name),
                               admin_url,
                               obj)
        else:
            # Don't display link to edit, because it either has no
            # admin or is edited inline.
            return no_edit_link

    to_delete = collector.nested(format_callback)

    protected = [format_callback(obj) for obj in collector.protected]
    model_count = {model._meta.verbose_name_plural: len(objs) for model, objs in collector.model_objs.items()}

    return to_delete, model_count, perms_needed, protected