<h4>Callback</h4>
<p>
  {{?optional}}
      If you specify the <em>{{name}}</em> parameter, it should
      specify a function that looks like this:
  {{:optional}}
      The <em>{{name}}</em> parameter should specify a function
      that looks like this:
  {{/optional}}
</p>
<pre>function({{#parameters}}{{+partials.variable_type}} {{name}}{{^last}}, {{/}}{{/}}) <span class="subdued">{...}</span>;</pre>
{{?description}}
<p>
  {{{description}}}
</p>
{{/description}}
{{?parameters}}
<dl>
  {{#parameters}}
    {{+partials.parameter_full}}
  {{/parameters}}
</dl>
{{/parameters}}