AJAX call inside Ember.RSVP.Promise

I have the following common code to invoke AJAX requests. My question is if the "return" keyword is necessary for the $.ajax (since doing $.ajax would anyways return a promise) OR if it is for some other purpose ?

doXhr: function(postData, requestUrl){  
    var promise = new Ember.RSVP.Promise(function(resolve, reject) {        
        return $.ajax({ //Is the "return" required on this line ?
            url: requestUrl,

        })
        .done(function(response, status, xhrObject) {         
          resolve(response);
        })
        .fail(function(xhrObject, status, error){           
            reject(errorObj);
        });
    })  
    return promise;
},