Bug 127105 Package explorer hierarchical mode calls ICompilationUnit#getChildren() in PackageExplorerProblemTreeViewer#isExpandable
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
if (fMemento != null)
			restoreUIState(fMemento);
		fMemento= null;
	
		 
		JavaUIHelp.setHelp(fViewer, IJavaHelpContextIds.PACKAGES_VIEW);
		
		fillActionBars();
		updateTitle();
		
		fFilterUpdater= new FilterUpdater(fViewer);
		ResourcesPlugin.getWorkspace().addResourceChangeListener(fFilterUpdater);
		
		
		
		
		if (isLinkingEnabled()) {
			IEditorPart editor= getViewSite().getPage().getActiveEditor();
			if (editor != null) {
				editorActivated(editor);
			}
		}
		
		stats.endRun();
	}
	private void initFrameActions() {
		fActionSet.getUpAction().update();
		fActionSet.getBackAction().update();
		fActionSet.getForwardAction().update();
	}