title: Sort by multiple columns with objectify
body: <p>I was wondering, if there is a way to sort a query using 2 columns not just one. I'm pretty sure <code>query.order("param1").order("param2")</code> ignores one param.</p>
  
  <p>Is it possible to sort using objectify with multiple columns?</p>
  
  <p>Here is my <code>@Entity</code></p>
  
  <pre><code>@Entity
  public class Operation {    
      @Id protected Long id;
      @Index protected Long creatorId;
      @Index protected Long categoryId;
      @Index protected Double value;
      @Index protected String description;
      @Index protected Date date;
  }
  </code></pre>