Bug 315281 update copyrights for 3.6
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/NavigatorContentDescriptorManager.java
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.WeakHashMap;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.internal.navigator.NavigatorPlugin;
import org.eclipse.ui.internal.navigator.NavigatorSafeRunnable;
import org.eclipse.ui.internal.navigator.Policy;
import org.eclipse.ui.internal.navigator.VisibilityAssistant;
import org.eclipse.ui.internal.navigator.VisibilityAssistant.VisibilityListener;
import org.eclipse.ui.navigator.INavigatorContentDescriptor;
import org.eclipse.ui.navigator.OverridePolicy;
import org.eclipse.ui.plugin.AbstractUIPlugin;
/**
 * @since 3.2
 */
public class NavigatorContentDescriptorManager {
	private static final NavigatorContentDescriptorManager INSTANCE = new NavigatorContentDescriptorManager();
	private final Map firstClassDescriptorsMap = new HashMap();
	private final Map allDescriptors = new HashMap();
	private class EvaluationCache implements VisibilityListener {