riance</span></span>
<span>    <span class="co">## for a difference contrast using the Ge et al. method</span></span>
<span>    <span class="co">## with robust HC0 sandwich variance</span></span>
<span>    <span class="va">marginal_fit</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://openpharma.github.io/beeca/reference/get_marginal_effect.html" class="external-link">get_marginal_effect</a></span><span class="op">(</span><span class="va">model</span>,</span>
<span>                     