$q.js

            console.log($q);
            function asyncGreet(name) {
                return $q(function(resolve, reject) {
                    console.log("timeout starts");
                    setTimeout(function() {
                        console.log("resolving");
                        console.log("resolve: ", resolve);
                        console.log(resolve('Hello, ' + name + '!'));
                    }, 2000);
                });
            }

            var prom = asyncGreet('Robin Hood');
            return prom
                .then(function(greeting) {
                    console.log('Success: ' + greeting);
                }, function(reason) {
                    console.log('Failed: ' + reason);
                });