title: How to find a model from a collection according to some attribute other than the ID?
body: <p>I have a model with several object:</p>
  
  <pre><code>//Model
  Friend = Backbone.Model.extend({
      //Create a model to hold friend attribute
      name: null,
  }); 
  
  //objects
  var f1 = new Friend({ name: "Lee" });
  var f2 = new Friend({ name: "David"});
  var f3 = new Friend({ name: "Lynn"});
  </code></pre>
  
  <p>and also, I will add these friends object to a collection:</p>
  
  <pre><code>//Collection
  Friends = Backbone.Collection.extend({
      model: Friend,
  });
  
  Friends.add(f1);
  Friends.add(f2);
  Friends.add(f3);
  </code></pre>
  
  <p>and now I want to get a model according to the name of the Friend. I know that I can add an <code>ID</code> attribute to achieve this. But I think there should have some more simple way to do this.</p>