w overlaps with the <code>nullBounds</code>.</p>
<p>To designate an era covariate to be the pre-exposure window, set <code>preExposure = TRUE</code> when
calling <code><a href="createEraCovariateSettings.html">createEraCovariateSettings()</a></code>. Note that, by default, <code>preExposure</code> will be <code>TRUE</code> if
<code>start</code> is smaller than 0.</p>
    </div>

    <div class="section level2">
    <h2 id="ref-usage">Usage<a class="anchor" aria-label="anchor" href="#ref-usage"></a></h2>
   