我试图通过这样的活动来隐藏UI中的元素

<plugin>

   <extension
         point="org.eclipse.ui.startup">
      <startup
            class="StartUp">
      </startup>
   </extension>

   <extension point="org.eclipse.ui.activities">  
<activity id="com.lowcoupling.actitivities.unwantedActionSet1" name="Unwanted Search ActionSet">  </activity>
<activityPatternBinding
      activityId="com.lowcoupling.actitivities.unwantedActionSet1"
      isEqualityPattern="true"
      pattern="org.eclipse.papyrus.infra.discovery.ui.menu.toolbars.discoveryCommand">
</activityPatternBinding>
 </extension>

</plugin>

但是当我将此插件作为另一个EClipse应用程序运行时，该按钮仍然存在。我究竟做错了什么？