Bug 315281 update copyrights for 3.6
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/NavigatorViewerDescriptor.java
return "ViewerDescriptor[" + viewerId + "]"; 
	}
	/**
	 * Update the popupMenuId. If a value is already set, then a warning message
	 * will be logged.
	 * 
	 * @param newPopupMenuId
	 *            The new popup menu id.
	 */
	 void setPopupMenuId(String newPopupMenuId) {
		if (newPopupMenuId != null) {
			if (popupMenuId != null) {
				NavigatorPlugin
						.log(
								IStatus.WARNING,
								0,
								NLS
										.bind(
												CommonNavigatorMessages.NavigatorViewerDescriptor_Popup_Menu_Overridden,
												new Object[] { getViewerId(),
														popupMenuId,
														newPopupMenuId }), null);
			}
			popupMenuId = newPopupMenuId;
		}
	}
	/**
	 * @param descriptor
	 *            A non-null descriptor to add
	 */