 with the <a href="api/ng/type/$rootScope.Scope"><code>$rootScope.Scope</code></a> Scope model observation
mechanism in angular, which means faster propagation of resolution or rejection into your
models and avoiding unnecessary browser repaints, which would result in flickering UI.</li>
<li><p>Q has many more features than $q, but that comes at a cost of bytes. $q is tiny, but contains
all the important functionality needed for common async tasks.</p>
<h1 id="testing">Testing</h1>
<pre><code class="lang-js