ifier">context</span><span class="special">,</span> <span class="identifier">Skipper</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">skipper</span>
      <span class="special">,</span> <span class="identifier">Attribute</span><span class="special">&amp;</span> <span class="identifier">attr</span><span class="special">)</span> <span class="keyword">const</span>
    <span class="special">{</span>
        <span class="comment">// ensure the attribute is actu