def METHOD_NAME(self, request, **kwargs):
    contenttype = self.get_content_type()
    # Validate data
    data = request.DATA.copy()
    data["content_type_id"] = contenttype.id
    validator = validators.UpdateAttachmentsOrderBulkValidator(data=data)
    if not validator.is_valid():
        return response.BadRequest(validator.errors)
    # Get and validate permissions
    item = contenttype.get_object_for_this_type(pk=data["object_id"])
    self.check_permissions(request, "bulk_update_order", item.project)
    if item.project.blocked_code is not None:
        raise exc.Blocked(_("Blocked element"))
    # Get after_attachment
    after_attachment = None
    after_attachment_id = data.get("after_attachment_id", None)
    if after_attachment_id is not None:
        after_attachment = get_object_or_error(item.attachments, request.user, pk=after_attachment_id)
    ret = services.update_order_in_bulk(item=item,
                                        after_attachment=after_attachment,
                                        bulk_attachments=data["bulk_attachments"])
    return response.Ok(ret)