[RxJS] just, return

Sometime, we migth just want to return a object which wrap into Observable. You can use 'just' or  'return'.

var source = Rx.Observable.return();

var subscription = source.subscribe(
    function (x) {
        console.log('Next: ' + x);
    },
    function (err) {
        console.log('Error: ' + err);
    },
    function () {
        console.log('Completed');
    });

// => Next: 42
// => Completed