</var>)

          </dt>

          <dd>

            Called to implement membership test operators. Should return true

            if <var>item</var> is in <var>self</var>, false otherwise. For

            mapping objects, this should consider the keys of the mapping

            rather than the values or the key-item pairs.

          </dd>

        </dl>

      </dd>

    </dl>

    

<h3> <a name="indexing_suite_subclasses"></a>indexing_suite sub-classes</h3>

    <p>

      The <tt>inde