Launch forward prediction for the new state given by some client.

def _on_state(self, state, client):
        """
        Launch forward prediction for the new state given by some client.
        """
        def cb(outputs):
            try:
                distrib, value = outputs.result()
            except CancelledError:
                logger.info("Client {} cancelled.".format(client.ident))
                return
            assert np.all(np.isfinite(distrib)), distrib
            action = np.random.choice(len(distrib), p=distrib)
            client.memory.append(TransitionExperience(
                state, action, reward=None, value=value, prob=distrib[action]))
            self.send_queue.put([client.ident, dumps(action)])
        self.async_predictor.put_task([state], cb)