public void testOptimizerSurrogate() throws Exception {
String rules = "\\U00020087 > x;"; // convert CJK UNIFIED IDEOGRAPH-20087 to an x
Transliterator custom = Transliterator.createFromRules("test", rules, Transliterator.FORWARD);
assertTrue(custom.getFilter() == null);
new ICUTransformFilter(new KeywordTokenizer(new StringReader("")), custom);
assertTrue(custom.getFilter().equals(new UnicodeSet("[\\U00020087]")));
}