Invalidate access tokens with a client/access token pair

        Returns:
            dict: Empty or error dict

def invalidate(self):
        """
        Invalidate access tokens with a client/access token pair

        Returns:
            dict: Empty or error dict
        """
        endpoint = '/invalidate'

        payload = {
            'accessToken': self.access_token,
            'clientToken': self.client_token,
        }
        self._ygg_req(endpoint, payload)
        self.client_token = ''
        self.access_token = ''
        self.available_profiles = []
        self.selected_profile = {}
        return True