 class="o">.</span><span class="n">set_xlabel</span><span class="p">(</span><span class="s2">&quot;a&#39;&quot;</span><span class="p">)</span>
        <span class="n">ax</span><span class="o">.</span><span class="n">set_ylabel</span><span class="p">(</span><span class="s2">&quot;b&#39;&quot;</span><span class="p">)</span>
    
    <span class="k">if</span> <span class="n">gamut_line_label</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
     