o">#&gt; Attaching package: 'HLMdiag'</span>
<span class="co">#&gt; The following object is masked from 'package:stats':</span>
<span class="co">#&gt; </span>
<span class="co">#&gt;     covratio</span>
<span class="fu"><a href="https://rdrr.io/r/utils/data.html">data</a></span><span class="op">(</span><span class="va">sleepstudy</span>, package <span class="op">=</span> <span class="st">"lme4"</span><span class="op">)</span>
<span class="va">sleep.lmer</span> <span class="op">&lt;-</span> <span class="fu">l