@VisibleForTesting
  public static UClassIdent create(String qualifiedName) {
    List<String> topLevelPath = new ArrayList<>();
    for (String component : Splitter.on('.').split(qualifiedName)) {
      topLevelPath.add(component);
      if (Character.isUpperCase(component.charAt(0))) {
        break;
      }
    }
    return create(Joiner.on('.').join(topLevelPath), qualifiedName);
  }
@Test
  public void serialization() {
    SerializableTester.reserializeAndAssert(UClassIdent.create("java.math.BigInteger"));
  }