Help with translations in Gramps

The narrative web is a good example.
If you want to use specific language for a report, You have to do the following:

        the_lang=self.menu.get_option_by_name(‘trans’).get_value()
        self.rlocale = self.set_locale(the_lang) # The lang you want to use (i.e. fr, de_AT...)
        self._ = self.rlocale.translation.sgettext

... and then you can use:

        self._("Your message")