<em>treeview</em> is the
Gtk::TreeView, on which it operates.
</p>
        </div>
      </div>

      <h3 class="section-bar">Public Instance methods</h3>

      <div id="method-M000128" class="method-detail">
        <a name="M000128"></a>

        <div class="method-heading">
          <a href="MenuExtension.src/M000128.html" target="Code" class="method-signature"
            onclick="popupCode('MenuExtension.src/M000128.html');return false;">
          <span class="method-name">add_item</span><span class