Bug 81877 Package explorer forgets active working set [package explorer]
3.1 M4 1. open pkg explorer. 2. select a working set, pkg explorer updates and filters out projects. 3. close pkg explorer. 4. open package explorer again and the working set is no longer applied. This used to work.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
}
	
	void toggleLayout() {
		
		fIsCurrentLayoutFlat= !fIsCurrentLayoutFlat;
		saveLayoutState(null);
		
		fContentProvider.setIsFlatLayout(isFlatLayout());
		fLabelProvider.setIsFlatLayout(isFlatLayout());
		
		fViewer.getControl().setRedraw(false);
		fViewer.refresh();
		fViewer.getControl().setRedraw(true);
	}
	
	/**
	 * This method should only be called inside this class
	 * and from test cases.
	 */
	public PackageExplorerContentProvider createContentProvider() {
		IPreferenceStore store= PreferenceConstants.getPreferenceStore();
		boolean showCUChildren= store.getBoolean(PreferenceConstants.SHOW_CU_CHILDREN);
		if (showProjects()) 
			return new PackageExplorerContentProvider(this, showCUChildren);
		else
			return new WorkingSetAwareContentProvider(this, showCUChildren, fWorkingSetModel);
	}
	
	private PackageExplorerLabelProvider createLabelProvider() {