lass="op">)</span></span>
<span></span>
<span><span class="co"># S4 method for class 'ROIVec,ROIVec'</span></span>
<span><span class="fu">concat</span><span class="op">(</span><span class="va">x</span>, <span class="va">y</span>, <span class="va">...</span><span class="op">)</span></span>
<span></span>
<span><span class="co"># S4 method for class 'DenseNeuroVol,missing'</span></span>
<span><span class="fu">concat</span><span class="op">(</span><span class="va">x</span>, <span class="va">y</span>, <span clas