"n">List</span><span class="p">,</span> <span class="n">np</span><span class="o">.</span><span class="n">ndarray</span><span class="p">]:</span>
    <span class="c1"># Make sure the estimated conditional variance is always &gt;= 0+epsilon to avoid ZeroDivisionError or exploding test statistics.</span>
    <span class="n">warning_msg</span> <span class="o">=</span> <span class="sa">f</span><span class="s2">&quot;&quot;&quot;At least one element of `conditional_var` is negative.</span><span class="se">\n</spa