Bug 163317 [Viewers] Take over SWT programming pattern to JFace Viewers
To open ColumnViewer for reusablility we should not make it final making the constructor protected forces people to subclass it and not directly creating instances from it.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/TableView.java
/**
	 * Init the menu for the receiver.
	 * 
	 * @param menu
	 */
	protected void initMenu(IMenuManager menu) {
		if (sortAction != null) {
			menu.add(sortAction);
		}
		addDropDownContributions(menu);
		if (filtersAction != null) {
			menu.add(filtersAction);
		}
		if (preferencesAction != null) {
			menu.add(preferencesAction);
		}
	}
	/**
	 * Add any extra contributions to the drop down.
	 * 
	 * @param menu
	 */
	void addDropDownContributions(IMenuManager menu) {
		
	}
	protected abstract void registerGlobalActions(IActionBars actionBars);
	protected abstract void fillContextMenu(IMenuManager manager);
	/*
	 * (non-Javadoc)
	 *