title: How to properly define backbone collection using typescript?
body: <p>I am using backbone.d.ts from <a href="https://github.com/borisyankov/DefinitelyTyped/" rel="nofollow">https://github.com/borisyankov/DefinitelyTyped/</a>.</p>
  
  <p>Typescript version 0.9.1</p>
  
  <p>Problem: I can't properly define Backbone.Collection:</p>
  
  <p>Code:</p>
  
  <pre><code>   /// &lt;reference path='./backbone/backbone.d.ts'/&gt;
  
     import Backbone = require("backbone");
  
     class User extends Backbone.Model {
          getName() : string {
          return "User Name";
          }
     }
  
     class Users extends Backbone.Collection {
          model = User;
     }
  
     var users = new Users();
  
     var firstUser = users.create({});
     console.log(firstUser.getName());
  </code></pre>
  
  <p>Trying to compile: <code>tsc ./users.ts -m amd</code>
  And I got the error:</p>
  
  <pre><code>error TS2094: The property 'getName' does not exist on value of type 'Backbone.Model'.
  </code></pre>
  
  <p>How to solve this problem?</p>