Edit in JSFiddle

var Gallery = {
    timeout: 3000,
    setTimeout: function (num) {
        this.timeout = num
    }
};

var myGallery = _.extend({}, Gallery);
myGallery.setTimeout(5000);
                         
var otherGallery = _.extend({}, Gallery);
otherGallery.setTimeout(1000);
                         
                       
describe("myGallery", function() {
    it('should have a timeout of 5000', function() {
        expect(myGallery.timeout).toEqual(5000);
    });
});
         
describe('otherGallery', function() {
    it('should have a timeout of 1000', function() {
        expect(otherGallery.timeout).toEqual(1000);
    });
});