Spring Data - MongoDb aggregation $ifNull
<pre><code>db.collection.aggregate([
    {$match : { name : "name" } },
    {$project: {
        name: 1,
        sent: { 
            $size: {
                "$ifNull": [ "$audience", [] ]
            } 
        }
    }
}]);
</code></pre>

<p>How can I do the above mongo aggregation with Spring data?</p>