ach threshold exceedance in the data.</p>
<p>If <code>cluster</code> is not supplied (is <code>NULL</code>) then it is
  assumed that each observation forms its own cluster.
  See <strong>Details</strong> for further details.</p></dd>


<dt>use_vcov</dt>
<dd><p>A logical scalar.  Should we use the <code>vcov</code> S3 method
for <code>x</code> (if this exists) to estimate the Hessian of the independence
loglikelihood to be passed as the argument <code>H</code> to
<code><a href="https://paulnorthrop.github.i