Bug 315281 update copyrights for 3.6
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/sorters/CommonSorterDescriptorManager.java
import org.eclipse.ui.internal.navigator.extensions.NavigatorContentDescriptor;
import org.eclipse.ui.internal.navigator.extensions.NavigatorContentRegistryReader;
import org.eclipse.ui.navigator.INavigatorContentDescriptor;
/**
 * @since 3.2
 * 
 */
public class CommonSorterDescriptorManager {
	private static final CommonSorterDescriptorManager INSTANCE = new CommonSorterDescriptorManager();
	private static final CommonSorterDescriptor[] NO_SORTER_DESCRIPTORS = new CommonSorterDescriptor[0];
	private final Map sortersMap = new HashMap();
	
	/**
	 * 
	 * @return An initialized singleton instance of the
	 *         CommonSorterDescriptorManager.
	 */
	public static CommonSorterDescriptorManager getInstance() {
		return INSTANCE;
	}
	private CommonSorterDescriptorManager() {
		new CommonSorterDescriptorRegistry().readRegistry();
	}
	/**
	 * 
	 * @param contentService
	 *            A content service to filter the visible filters.
	 * @param aParent
	 *            The parent used to search for a sorter.
	 * @return The set of filters that are 'visible' to the given viewer