returnTrue and returnFalse functions in jQuery source
<p>I can't help but notice there are two seemingly useless functions in the source code of jQuery (For v1.9.1, it's line 2702 and line 2706):</p>

<pre><code>function returnTrue() {
    return true;
}

function returnFalse() {
    return false;
}
</code></pre>

<p>Which both are called quite often within jQuery. Is there a reason why they don't simply substitute the function call with a boolean <code>true</code> or <code>false</code>?</p>
