 class="fu"><a href="../reference/rename_to_piece_byname.html">rename_to_piece_byname</a></span><span class="op">(</span><span class="va">m_pieces</span>, piece <span class="op">=</span> <span class="st">"pref"</span><span class="op">)</span></span>
<span><span class="co">#&gt;             Motors Cars LED lamps</span></span>
<span><span class="co">#&gt; Electricity      1    2         3</span></span>
<span><span class="co">#&gt; Electricity      4    5         6</span></span>
<span><span class="fu"><a href=