>returns best iteration based on a given metric. By default, uses the first scoring metric</p></dd>
</dl>
    
    <h2 class="hasAnchor" id="arguments"><a class="anchor" href="#arguments"></a>Arguments</h2>

    
    <dl class='dl-horizontal'>
 <dt>trainer</dt><dd><p>superml trainer object, could be either XGBTrainer, RFTrainer, NBTrainer etc.</p></dd>
 <dt>parameters</dt><dd><p>list containing parameters</p></dd>
 <dt>n_folds</dt><dd><p>number of folds to use to split the train data</p></dd>
 <dt>scoring</