def authorize(self, http):
raise NotImplementedError<EOL>
Take an httplib2.Http instance (or equivalent) and authorizes it.

        Authorizes it for the set of credentials, usually by replacing
        http.request() with a method that adds in the appropriate headers and
        then delegates to the original Http.request() method.

        Args:
            http: httplib2.Http, an http object to be used to make the refresh
                  request.