hl kwa">function</span><span class="hl opt">(</span>child<span class="hl opt">,</span> parent<span class="hl opt">) {</span> <span class="hl kwa">for</span> <span class="hl opt">(</span><span class="hl kwa">var</span> key <span class="hl kwa">in</span> parent<span class="hl opt">) {</span> <span class="hl kwa">if</span> <span class="hl opt">(</span>__hasProp<span class="hl opt">.</span><span class="hl kwd">call</span><span class="hl opt">(</span>parent<span class="hl opt">,</span> key<span class="hl opt">))