tts_project/public/assets/mockup/ajax/Testing-Bob.js

Testing.prototype.Bob = function() {
    let dp = new tts.DeferredPromise();
    tts.when([this.loadLeft(), this.loadRight()]).then(val=>{
        dp.resolve("All Done");
    });
    return dp;
};

Testing.prototype.loadLeft = function() {
    let dp = new tts.DeferredPromise();
    console.log("Left");
    dp.resolve();
    return dp;
};
Testing.prototype.loadRight = function() {
    let dp = new tts.DeferredPromise();
    dp.then(val=>{
        alert(this.tab);
    });
    dp.resolve();
    return dp;
};