title: Filtering a Backbone Collection returns an array of Models
body: <p>Sample Code:</p>
  
  <pre><code>this.books = this.getBooksFromDatabase();
  this.publishedBooks = this.books.filter(function(book) {
    return book.get("isPublished") === "1";
  });
  </code></pre>
  
  <p>Here lies the problem:</p>
  
  <p>this.books.filter, returns an array of the models. I've tried wrapping the array, as such:</p>
  
  <pre><code>var publishedBooks = _( this.books.filter(function(book) {
    return book.get("isPublished") === "1";
  }))
  </code></pre>
  
  <p>as recommended by this post:
  <a href="https://github.com/documentcloud/backbone/issues/120" rel="noreferrer">https://github.com/documentcloud/backbone/issues/120</a></p>
  
  <p>But i still can't run things like:
  publishedBooks.each(...), or
  publishedBooks.get(...)</p>
  
  <p>What am I missing? Is there a way to convert the returned array into a collection?</p>