title: Getting all users with a Role in Liferay
body: <p><em>I'm new to Liferay development in general, so feel free to point out if I'm going about stuff totally the wrong way.</em></p>
  
  <p>I'm trying to get a DynamicQuery object of all users within a certain group (I'll use this object to further filter another query I'll do against the message board). The <code>User</code> interface seems to have a <code>roleIds</code> property that I might be able to use, since I already know the <code>roleId</code> I'm interested in. But I can't find the proper way to query if <code>roleIds</code> <em>contains</em> a certain value.</p>
  
  <p>Any ideas on what I want to do?</p>
  
  <p>PS: I would have the exact SQL query I could ask directly, but I'd rather use Liferay's own connection pool, without needing to do some weird ext project thingy.</p>