@Override
  public @Nullable ASTNode findChildByRole(int role) {
    LOG.assertTrue(ChildRole.isUnique(role));
    switch (role) {
      case ChildRole.PACKAGE_STATEMENT:
        return findChildByType(JavaElementType.PACKAGE_STATEMENT);

      case ChildRole.IMPORT_LIST:
        return findChildByType(JavaElementType.IMPORT_LIST);

      default:
        return null;
    }
  }
@Override
  public @Nullable ASTNode findChildByRole(int role)