title: ruby sort_by twice
body: <p>Ruby has a sort_by method on Enumerables.  Fantastic!  So you can do something like</p>
  
  <pre><code>entries.sort_by { |l| l.project.name }
  </code></pre>
  
  <p>That would sort a bunch of entries by their project names.  How could you work it so that within projects that had the same name, entries were sorted by their time?</p>