les/reeb/mergetree.html#cereeberus.reeb.merge.MergeTree.add_label_edge">[docs]</a>
    <span class="k">def</span> <span class="nf">add_label_edge</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">u</span><span class="p">,</span> <span class="n">v</span><span class="p">,</span> <span class="n">w</span><span class="p">,</span> <span class="n">f_w</span><span class="p">,</span> <span class="n">label</span> <span class="o">=</span> <span class="kc">None</span><sp