   <span class="comment">// Read just the header. Otherwise, the empty_body</span>
    <span class="comment">// would generate an error if body octets were received.</span>
    <span class="identifier">read_header</span><span class="special">(</span><span class="identifier">stream</span><span class="special">,</span> <span class="identifier">buffer</span><span class="special">,</span> <span class="identifier">req0</span><span class="special">);</span>

    <span class="comment">// Choose a body depending on