title: How to generate asset URL from within a service?
body: <p>I'm using Symfony 2 and I want to generate the absolute url to an asset from a service class, not a template. I'd like the same thing that</p>
  
  <pre><code>{{ asset('/path/to/my/asset') }}
  </code></pre>
  
  <p>would return in a template.</p>
  
  <p>Is this possible?</p>