al_dir</span><span class="p">:</span> <span class="nb">str</span><span class="p">,</span> <span class="n">metric</span><span class="p">:</span> <span class="n">Optional</span><span class="p">[</span><span class="nb">str</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;episode_reward_mean&#39;</span><span class="p">,</span> <span class="n">mode</span><span class="p">:</span> <span class="n">Optional</span><span class="p">[</span><span class="nb">str</span><span class="p">]</span>