Bug 114492 [WorkingSets] working sets: edit dialog should not display an error on open
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/workingsets/JavaWorkingSetPage.java
if (resource != null && !resource.isAccessible())
				return;
		}
		Object parent= fTreeContentProvider.getParent(child);
		if (parent == null)
			return;
		boolean allSameState= true;
		Object[] children= null;
		children= fTreeContentProvider.getChildren(parent);
		for (int i= children.length -1; i >= 0; i--) {
			if (fTree.getChecked(children[i]) != baseChildState || fTree.getGrayed(children[i])) {
				allSameState= false;
				break;
			}
		}
	
		fTree.setGrayed(parent, !allSameState);
		fTree.setChecked(parent, !allSameState || baseChildState);
		
		updateParentState(parent, baseChildState);
	}
	private void initializeCheckedState() {
		BusyIndicator.showWhile(getShell().getDisplay(), new Runnable() {
			public void run() {
				Object[] elements;
				if (fWorkingSet == null) {
					
					IWorkbenchPage page= JavaPlugin.getActivePage();
					if (page == null)
						return;