title: Cancan accessible_by
body: <p>What exactly is happening when I do:</p>
  
  <pre><code>@patient.course_enrollments.accessible_by(current_ability)
  </code></pre>
  
  <p>What seems to happen is I get course_enrollments where <code>course.client_id = user.client.id</code>, I just don't understand how <code>accessible_by</code> works.</p>
  
  <pre><code># ability.rb
  can :manage, CourseEnrollment, :course =&gt; {:client_id =&gt; user.client.id}
  </code></pre>