uffer, and always uses the faster
          approach on the first call. So the effects of the flush parameter in this
          implementation are on the return value of <code class="computeroutput"><span class="identifier">write</span></code>
          as noted below, when <code class="computeroutput"><span class="identifier">write</span></code>
          returns early when <a class="link" href="../boost__beast__zlib__Flush.html" title="zlib::Flush"><code class="computeroutput"><span class="identifier">Flu