Promise 同浏览器接口，控制台输出。
<script src="../lib/promise.js"></script>
<script>
var p = new Promise(function(resolve, reject){
    resolve(1);
}).then(function(data){
    console.log(data);
    throw 3;
}).then(function(){

}, function(err){
    console.log(err);
    return 4;
}).then(function(data){
    console.log(data)
    throw 2;
})
</script>