private void assertTransform(
     String message, String expected, StringTransform t, StringTransform back, String... source) {
   for (String s : source) {
     assertEquals(message + " " + s, expected, t.transform(s));
   }
   assertEquals(message + " " + expected, source[0], back.transform(expected));
 }
 private void assertTransform(String message, String expected, StringTransform t, String source) {
   assertEquals(message + " " + source, expected, t.transform(source));
 }