etwork requests: they can even be simple things like asking for location access permission before firing a request.</em></p>
</blockquote>

<p>A common use of a constraint would be an <strong>OAuth Constraint</strong>, which makes sure you have an OAuth token before your requests start.</p>

<p>To create a constraint, just subclass <code><a href="Classes/Constraint.html">Constraint</a></code>, and override the two required methods:</p>
<pre class="highlight swift"><code><span class="kd">class</span> <span c