<span class="token literal-property property">lastName</span><span class="token operator">:</span> <span class="token keyword">null</span><span class="token punctuation">,</span>

  <span class="token function-variable function">fullName</span><span class="token operator">:</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token parameter">key<span class="token punctuation">,</span> value<span class="token punctuation">,</span> previousValue</span><span c