<p>Clear all elements in the attribute vector array of pointer on the next particle/cells in the tree data-structure. Override by the child class. </p>
<p>Return the attribute vector array of pointer on the next particle/cells in the tree data-structure. Override by the child class.</p>
<dl class="section return"><dt>Returns</dt><dd>_next attribute vector array of pointer on the next particle/cells in the tree data-structure </dd></dl>