Bug 143430 [CommonNavigator] CommonNavigator requires initialInput to be Adaptable
I have a root nodes that is not Adaptable and that does not fit well with CommonNavigator.getInitialInput which requires (for no real good reason ?) to be Adaptable. Should this not just be an Object ?
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
if (adapter == COMMON_VIEWER_CLASS) {
			return getCommonViewer();
		} else if (adapter == INAVIGATOR_CONTENT_SERVICE) {
			return getCommonViewer().getNavigatorContentService();
		} else if (adapter == ISHOW_IN_TARGET_CLASS) {
			return this;
		} else if (adapter == ISHOW_IN_SOURCE_CLASS) {
            return getShowInSource();
        }
		return super.getAdapter(adapter);
	}
    /**
     * Returns the <code>IShowInSource</code> for this view.
     */
    private IShowInSource getShowInSource() {
        return new IShowInSource() {
            public ShowInContext getShowInContext() {
                return new ShowInContext(getCommonViewer().getInput(), getCommonViewer().getSelection());
            }
        };
    }
	/**
	 * @return The Navigator Content Service which populates this instance of
	 *         Common Navigator
	 */
	public NavigatorActionService getNavigatorActionService() {
		return commonManager.getNavigatorActionService();
	}
	/**
	 * <p>