<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def url_map(self, for_user=None, **kwargs):
 """ Returns a dictionary of urls mapped to Displayable subclass instances, including a fake homepage instance if none exists. Used in ``yacms.core.sitemaps``. """

        class Home:
            title = _("Home")
        home = Home()
        setattr(home, "get_absolute_url", home_slug)
        items = {home.get_absolute_url(): home}
        for model in apps.get_models():
            if issubclass(model, self.model):
                for item in (model.objects.published(for_user=for_user)
                                  .filter(**kwargs)
                                  .exclude(slug__startswith="http://")
                                  .exclude(slug__startswith="https://")):
                    items[item.get_absolute_url()] = item
        return items