Bug 31683 Show In doesn't work for class file in rt.jar
I20030611 - create Test project that uses Jar container - open NumberFormat.class - activate Show In... and choose Package Explorer Observe: NumberFormat.class doesn't get revealed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
implements ISetSelectionTarget, IMenuListener,
		IShowInTarget,
		IPackagesViewPart,  IPropertyChangeListener, 
		IViewPartInputProvider {
	
	private boolean fIsCurrentLayoutFlat; 
	private static final int HIERARCHICAL_LAYOUT= 0x1;
	private static final int FLAT_LAYOUT= 0x2;
	
	public final static String VIEW_ID= JavaUI.ID_PACKAGES;
				
	
	static final String TAG_SELECTION= "selection"; 
	static final String TAG_EXPANDED= "expanded";