ss="n">precede</span><span class="p">(</span><span class="n">task2</span><span class="p">);</span>

<span class="w">  </span><span class="n">executor</span><span class="p">.</span><span class="n">run</span><span class="p">(</span><span class="n">taskflow</span><span class="p">).</span><span class="n">wait</span><span class="p">();</span>

<span class="w">  </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span></pre><pre class="m