 problem type.</p>
<p>For features and targets, it can be one of the following format:</p>
<ul>
<li>tuple of list</li>
<li>generator of tuple</li>
</ul>
<p>Please note that if preprocessing function returns generator of tuple, then corresponding problem cannot be chained using <code>&amp;</code>.</p>

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<h3 id="Tuple-of-List">Tuple of List<a class=