title: Liferay API: Get Roles via Permissions
body: <p>At the moment I'm trying to create an overview where I list all the Layouts and Portlets and Roles (Permissions) that are activated for every of them. </p>
  
  <p>I think I'm pretty near to the solution already but the last bit is missing.</p>
  
  <p>I already got all kind of information I need. I got form Layout --> to Resource --> to Permission. But now I don't know how to get from the Permissions (or permissionId) to the actual Roles via the Liferay API. </p>
  
  <p>what I have: Layout, Resource, Permission
  what I need: Roles</p>
  
  <p>Using Liferay 5.2.4</p>