private static Set<String> computeFileNameRefs(
CompilationUnitDeclaration cud,
final Map<String, String> binaryTypeToSourceFileMap) {
final Set<String> result = new HashSet<String>();
cud.traverse(new TypeRefVisitor(cud) {
@Override
protected void onBinaryTypeRef(BinaryTypeBinding referencedType,
CompilationUnitDeclaration unitOfReferrer, Expression expression) {
String fileName = binaryTypeToSourceFileMap.get(String.valueOf(referencedType.getFileName()));
if (fileName != null) {