Bug 231119 [GlobalActions] RefreshAction markes as @noextend but should be
3.4 Javadoc says: * This class may be instantiated; it may also subclass to extend: * .... The tag * @noextend This class is not intended to be subclassed by clients. got added, which is different. In JDT we subclass RefreshAction to add extra operations to refresh.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/RefreshAction.java
Iterator resourcesEnum = resources.iterator();
				try {
					while (resourcesEnum.hasNext()) {
						try {
							IResource resource = (IResource) resourcesEnum
									.next();
							refreshResource(resource, new SubProgressMonitor(
									monitor, 1000));
						} catch (CoreException e) {
							errors = recordError(errors, e);
						}
						if (monitor.isCanceled()) {
							throw new OperationCanceledException();
						}
					}
					if (errors != null) {
						errorStatus[0] = errors;
					}
				} finally {
					monitor.done();
				}
			}
		};
	}
	/**
	 * Refresh the resource (with a check for deleted projects).
	 * <p>
	 * This method may be extended to refresh model objects related to the
	 * resource.
	 * </p>