lues of test data</span>
<span class="sd">            |   None defaults to the one set in lx.xyz_to_lab()</span>
<span class="sd">        :xyzwr:</span>
<span class="sd">            | None or ndarray, optional</span>
<span class="sd">            |    Whitepoint tristimulus values of reference data</span>
<span class="sd">            |    None defaults to the one set in lx.xyz_to_lab()</span>
<span class="sd">        :DEtype:</span>
<span class="sd">            | &#39;jab&#39; or str, optional</span>
<span c