ents<a class="anchor" aria-label="anchor" href="#arguments"></a></h2>
    <dl><dt>name</dt>
<dd><p>a short name identifier.  Must be alphanumeric.</p></dd>


<dt>label</dt>
<dd><p>a longer, human readable label that can have other characters
such as spaces, hyphens, etc.</p></dd>


<dt>metric</dt>
<dd><p>a function with arguments "model" and "out" (and optionally
"draw")</p></dd>

</dl></div>

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