title: How to create a stub for relation models
body: <p>I have created hasManyThrough relation for 2 model
  Like: this.repository.operations(id).create(operation);</p>
  <p>I am able to create operation and relation for it. But when I am trying to write test cases for those methods having issues.</p>
  <pre class="lang-js prettyprint-override"><code>repository.stubs.create.resolves('test');
  </code></pre>
  <p>can anyone help me to create a stub for</p>
  <pre class="lang-js prettyprint-override"><code>
  this.repository.operations(id).create(operation);
  </code></pre>
  <p>Thanks.</p>