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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def authenticate_redirect(self, callback_uri=None, ask_for=["name", "email", "language", "username"]):
 """ Performs a redirect to the authentication URL for this service. After authentication, the service will redirect back to the given callback URI. We request the given attributes for the authenticated user by default (name, email, language, and username). If you don't need all those attributes for your app, you can request fewer with the |ask_for| keyword argument. """

        callback_uri = callback_uri or request.url
        args = self._openid_args(callback_uri, ax_attrs=ask_for)
        return redirect(self._OPENID_ENDPOINT +
                        ("&" if "?" in self._OPENID_ENDPOINT else "?") +
                        urllib.urlencode(args))