ember different controller for a property

I have a session and a test. Session holds many tests - so in the model it is a DS.HasMany.

The view has a tests table, and I want it to be sortable. So the question is - how can I define a tests controller to the tests "property" in session

session.hbs:

<div class="main-container">
    <h1>session {{id}}</h1>

    <table class="tests-table table table-bordered">
        <tr>
            <th>ID</th>
            <th>Logical ID</th>
            <th>name</th>
        </tr>
      {{#each test in tests}}
          <tr>
              <td>{{test.id}}</td>
              <td>{{test.logicalId}}</td>
              <td>{{test.name}}</td>
          </tr>
      {{/each}}
    </table>
</div>

routes/session.js:

import Ember from 'ember';

export default Ember.Route.extend({
  model: function(params) {
    return Ember.RSVP.hash({
      session: this.get('store').find('session', params.session_id),
      tests: this.get('store').find('test', {
        session_id: params.session_id
      })
    });
  },

  setupController: function(controller, model) {
    controller.set('model', model.session);
    var testsController = this.controllerFor('tests');
    testsController.set('model', model.tests);
  }
});