How to use the atelier.rstgen function in atelier

def menu2rst(self, ar, mnu, level=1):
        """Used by :meth:`show_menu`."""

        if not isinstance(mnu, Menu):
            return str(mnu.label)

        has_submenus = False
        for i in mnu.items:
            if isinstance(i, Menu):
                has_submenus = True
        items = [self.menu2rst(ar, mi, level + 1) for mi in mnu.items]
        if has_submenus:
            s = rstgen.ul(items).strip() + '\n'
            if mnu.label is not None:
                s = str(mnu.label) + ' :\n\n' + s
        else:
            s = ', '.join(items)
            if mnu.label is not None:
                s = str(mnu.label) + ' : ' + s
        return s

field=title, model=model_ref(fld.model)))
                s += '\n\n'
                s += rstgen.header(level, _("%s (field)") % title)
                if len(self.content) > 1:
                    s += '\n'.join(self.content[1:])
                    s += '\n\n'
                return s

            if isinstance(cls, Plugin):
                s = ''
                title = str(cls.verbose_name)
                s += "\n.. index::\n   single: "
                s += str(_('%s (app)') % title)
                s += '\n\n.. _' + name + ':\n'
                s += '\n'
                s += rstgen.header(level, _("%s (app)") % title)
                return s

            if not isinstance(cls, type):
                raise Exception("%s is not an actor." % self.content[0])

            if issubclass(cls, models.Model):
                model = cls

                s = ''
                name = model_name(model).lower()
                title = force_text(model._meta.verbose_name)
                s += "\n.. index::\n   single: "
                s += str(_('%(model)s (model in %(app)s)') % dict(
                    model=title, app=model._meta.app_label))

                s += '\n\n'