Bug 221521 [Markers] New markers API needs to be pared down
We have too much API in some of the new classes and they can be moved to internals
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkerFieldFilterGroup.java
protected CachedMarkerBuilder builder;
	private IConfigurationElement element;
	private Map EMPTY_MAP = new HashMap();
	private boolean enabled = true;
	protected MarkerFieldFilter[] fieldFilters;
	private int scope;
	private String name;
	private String id;
	/**
	 * The entry for testing filters. Cached to prevent garbage.
	 */
	private MarkerEntry testEntry = new MarkerEntry(null);
	private IWorkingSet workingSet;
	private Collection workingSetPaths;
	/**
	 * Create a new instance of the receiver.
	 * 
	 * @param configurationElement
	 * @param markerBuilder
	 */
	public MarkerFieldFilterGroup(IConfigurationElement configurationElement,
			CachedMarkerBuilder markerBuilder) {
		element = configurationElement;
		builder = markerBuilder;
		initializeWorkingSet();
		scope = processScope();
		if (configurationElement == null)
			return;
		String enablementString = configurationElement
				.getAttribute(MarkerSupportRegistry.ENABLED);