title: How to catch the xhr object for Backbone.save
body: <pre><code>App.commands.setHandler "when:fetched", (entities, callback) -&gt;
    xhrs = _.chain([entities]).flatten().pluck("_fetch").value()
    $.when(xhrs...).done -&gt;
      callback()
  </code></pre>
  
  <p>we have the above code to catch the xhr object from fetch calls. How can i catch the xhr object from save method (for all post,put and delete types). I am getting undefined for the save method. </p>