'Authenticates and authorizes for the given Google resource.
Some of the available resources which can be used in the ``oauth_scope``
argument are:
* Gmail Contacts - http://www.google.com/m8/feeds/
* Calendar - http://www.google.com/calendar/feeds/
* Finance - http://finance.google.com/finance/feeds/
You can authorize multiple resources by separating the resource
URLs with a space.
.. versionchanged:: 3.1
Returns a `.Future` and takes an optional callback.  These are
not strictly necessary as this method is synchronous,
but they are supplied for consistency with
`OAuthMixin.authorize_redirect`.'

@return_future
def authorize_redirect(self, oauth_scope, callback_uri=None, ax_attrs=['name', 'email', 'language', 'username'], callback=None):

    callback_uri = (callback_uri or self.request.uri)
    args = self._openid_args(callback_uri, ax_attrs=ax_attrs, oauth_scope=oauth_scope)
    self.redirect(((self._OPENID_ENDPOINT + '?') + urllib_parse.urlencode(args)))
    callback()
