quirements">Concept Requirements</a>
</h3></div></div></div>
<p>
          In the table below, <code class="computeroutput"><span class="identifier">X</span></code> denotes
          a model of <code class="computeroutput"><span class="identifier">Extractor</span></code> and
          <code class="computeroutput"><span class="identifier">a</span></code> denotes an instance of
          a Python object type.
        </p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
</colgroup