Waiting completed several requests using Reflux Actions

Question

First, init app. I called many Async Reflux Actions requests:

    ExpenActions.loadAccounts();
    WareActions.load();
    ProdActions.load();
    NotifActions.load();

It's all request created like this:

import Reflux from 'reflux';

const WareActions = Reflux.createActions({

    load: { asyncResult: true },
});

---

    onLoad() {
        console.log("start load...")

        return yajax.get(this._prefix+'warehouse/get').then(
            Actions.load.completed, 
            Actions.load.failed);
    },

    onLoadCompleted(data) {
        console.log("completed load", data);

        this.setState({
            rows: (data.success) ? data.data : [],
            isLoaded: false
        })
    },

    onLoadFailed() {
        console.log("failed load");
    },

I can wait for each request separately .. but how do I hang an event on when all events are finished?

Promise.all doesn't work.. because WareActions.load() returned undefined... not Promise..