ss="lineno">  309</span>&#160;        <span class="keyword">protected</span>:</div><div class="line"><a name="l00310"></a><span class="lineno">  310</span>&#160;            <a class="code" href="class_std_large_vec_3_01_vecd_01_4.html">StdLargeVec&lt;Vecd&gt;</a> &amp;viscous_force_from_fluid_;</div><div class="line"><a name="l00311"></a><span class="lineno">  311</span>&#160;            Vecd ReduceFunction(<span class="keywordtype">size_t</span> index_i, Real dt = 0.0) <span class="keyword">override</span>