title: How can I change the font size of a Gtk.Label in vala?
body: <p>I'm a Vala/Gtk newbie and I'm trying to change the font size of a Gtk.Label, but I can't find a good way to do it.</p>
  
  <p>I find out that I can use the markup like this :</p>
  
  <pre><code>    var welcome_message = new Gtk.Label ("&lt;span size='17000'&gt;Hello&lt;/span&gt;");
      welcome_message.set_use_markup (true);
  </code></pre>
  
  <p>But it seems a little hackish.
  What is the right way to do it ?</p>