How to set dynamically an associated model?

I have a model class "User" that has an association with "Job":

Code:

Ext.define('Fiddle.model.User', {
    extend: 'Fiddle.model.Base',


    fields: [{
        name: 'name',
        type: 'string'
    }, {
        name: 'jobId',
        type: 'int',
        reference: 'Job'
    }]
});

When I do below code it works properly:

Code:

var user = Fiddle.model.User.load(1);
alert(user.job.get('name')); //It works

But I am not able to create a model with association. I tried:

Code:

var newUser = Ext.create('Fiddle.model.User');
newUser.set({name: 'Bill', job: {id: 2, name: 'developer'}});
alert(newUser.job.get('name')); //It breaks because there is no job associated

How could I do this?

Here you can see the fiddle: http://ift.tt/1r4JM5Q

Thanks

How to set dynamically an associated model?