an> <span class="st">"best.test"</span><span class="op">)</span></span></code></pre></div>
<p>for two distinct reasons:</p>
<ol style="list-style-type: decimal">
<li><p>When <code>data</code> remains unspecified, its default is
<code>data = "train"</code>. Thus, asking for
<code>tree = "best.test"</code> would require switching to
<code>data = "test"</code>.</p></li>
<li><p>More crucially, <code>titanic.fft</code> was created without any
test data. Hence, asking for the best test tree does not make sense �