constructor(store) {
    ... initilaize websocket
    store.subscribe = sendMessage
}
sendMessage(action) {
    if(action.type === SEND_MESSAGE) {
        ...
    }
}

function sendMessage(id, payload) {
  return {
    type: SEND_MESSAGE,
    payload,
    id
  }
}

function sendMessage(id, payload) {
  return dispatch => {
    websocket.emit({ id, payload })
    dispatch(sentMessage())
  }
}

    function sendMessage(id, payload) {
      return {
        type: SEND_MESSAGE,
        id,
        payload
      }
    }

    const websocketMiddleware = store => next => action => {
      switch (action.type) {
        case SEND_MESSAGE:
          socket.emit(...)
          return next(action);
        case RECEIVE_MESSAGE:
          // read the message.. somehow...
          return next(action);
      }
    }

   const store = applyMiddleware(websocketMiddleware)(createStore(reducer))