Eclipse Plugin Development - Hide "Build Working Set" under Project menu

I successfully removed "Build All" "Build Project" "Clear..." "Build Automatically" and "Generate Java docs" from the PROJECT Menu. I am using Activity to hide them.

But I am not able to remove "Build Working Set" at all.

I can't get its ID from Plugin-In Menu Spy
I tried to search its id in Plugin-registry. But I couldn't get anything useful.

Please help me removing this from the project menu, as this command is not needed in my perspective.

Solution

This menu is added by the Eclipse RCP action builder org.eclipse.ui.internal.ide.WorkbenchActionBuilder in the addWorkingSetBuildActions:

private void addWorkingSetBuildActions(MenuManager menu) {
    buildWorkingSetMenu = new MenuManager(IDEWorkbenchMessages.Workbench_buildSet);
    IContributionItem workingSetBuilds = new BuildSetMenu(window,
            getActionBarConfigurer());
    buildWorkingSetMenu.add(workingSetBuilds);
    menu.add(buildWorkingSetMenu);
}

Unfortunately the MenuManager constructor this is using doesn't specify an id, so I don't think you can use an activity to suppress it.