def refresh_token(self):
        """  Refreshes access token using refresh token. Returns true if successful, false otherwise. """

        try:
            if self.token:
                self.token = self.request().refresh_token(self.refresh_url, self.token['refresh_token'])
                return True
        except Exception as e:
            # TODO: what might go wrong here - handle this error properly
            #print("Unexpected error:\t\t", str(e))
            #traceback.print_exc()
            pass
        return False
Refreshes access token using refresh token. Returns true if successful, false otherwise.