keyword">struct </span>callback_holder {</div><div class="line"><a name="l00265"></a><span class="lineno">  265</span>&#160;    subscribe_callback_t subscribe_callback;</div><div class="line"><a name="l00266"></a><span class="lineno">  266</span>&#160;    acknowledgement_callback_t acknowledgement_callback;</div><div class="line"><a name="l00267"></a><span class="lineno">  267</span>&#160;  };</div><div class="line"><a name="l00268"></a><span class="lineno">  268</span>&#160;</div><div class="line"><a name=