it
is easy to introduce bugs where properties are not yet synchronized:</p>
<pre class="language-javascript line-numbers"><code class="javascript language-javascript">Person<span class="token punctuation">.</span><span class="token function">reopen</span><span class="token punctuation">(</span><span class="token punctuation">{</span>
  <span class="token literal-property property">lastNameChanged</span><span class="token operator">:</span> Ember<span class="token punctuation">.</span><span class="token func