keyword">trait</span> Ladder<span class="token punctuation">[</span>F<span class="token punctuation">[</span>_<span class="token punctuation">,</span> _<span class="token punctuation">]</span><span class="token punctuation">]</span> <span class="token punctuation">{</span>
  <span class="token keyword">def</span> submitScore<span class="token punctuation">(</span>userId<span class="token operator">:</span> UserId<span class="token punctuation">,</span> score<span class="token operator">:</span> Score<span c