tainer_type</span><span class="special">&amp;</span> <span class="identifier">headers</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">headers_</span><span class="special">;</span> <span class="special">}</span>
  <span class="identifier">headers_container_type</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">headers</span><span class="special">()</span> <span class="keyword">