title: Is there a need for both caching 'this' and set its context in backbone.js?
body: <p>This code is from backbone.js, within the render method of a view. I noticed that the author had both cached 'this' to the var 'that', and also set the context to this. Is there any reason for both caching 'this' and also explicitly set the context? It seems to work with just one of them at works.</p>
  
  <pre><code>render: function () {
      var that = this;
      _.each(this.collection.models, function (item) {
          that.renderContact(item);
      }, this);
  },
  </code></pre>